GB2642045A

GB2642045A - Apparatus, method, and computer program

Info

Publication number: GB2642045A
Application number: GB2408860.1A
Authority: GB
Inventors: Rezaie Sajad; Barbu Oana-Elena; Johannes Korpi Dani; Gold Dimitri
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2024-06-20
Filing date: 2024-06-20
Publication date: 2025-12-31
Also published as: GB202408860D0; WO2025262546A1

Abstract

An apparatus comprising: means for transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; means for receiving, from the base station, configuration information based on the capability information; and means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information. The capability information may indicate a capability to support pilotless transmissions. The apparatus may comprise means for transmitting, to the base station, configuration information indicating at least one of: a mask of resource elements for pilotless transmissions; an index of a mask of resource elements for pilotless transmissions; or a configuration parameter to reconstruct a mask of resource elements for pilotless transmissions. The mask of resource elements for pilotless transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols. The configuration information may be received via radio resource control, RRC, downlink control information, DCI or medium access control, MAC, control element.

Description

[0001] APPARATUS, METHOD, AND COMPUTER PROGRAM

[0002] Field of the disclosure

[0003] The present disclosure relates to an apparatus, a method, and a computer program for managing pilotless transmissions and pilot-based transmissions in a communication system.

[0004] Background

[0005] A communication system can be seen as a facility that enables communication sessions between two or more entities such as communication devices, base stations and/or other nodes by providing carriers between the various entities involved in the communications path.

[0006] The communication system may be a wireless communication system. Examples of wireless systems comprise public land mobile networks (PLMN) operating based on radio standards such as those provided by 3GPP, satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

[0007] The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. Examples of standard are 40, 50 or 60 standards.

[0008] Summary

[0009] According to an aspect there is provided an apparatus comprising: means for transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; means for receiving, from the base station, configuration information based on the capability information; and means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0010] The capability information may indicate a capability to support pilotless transmissions.

[0011] The apparatus may comprise: means for transmitting, to the base station, configuration information indicating at least one of: a mask of resource elements for pilotless transmissions; an index of a mask of resource elements for pilotless transmissions; or a configuration parameter to reconstruct a mask of resource elements for pilotless transmissions.

[0012] Generating data symbols may comprise: encoding data bits to generate encoded data bits; modulating some of encoded bits to generate data symbols; modulating other of the encoded data bits to generate data symbols acting as virtual pilot symbols.

[0013] The configuration information may indicate at least one of: a request to perform pilotless transmissions; a mask of resource elements for pilotless transmissions; an index of mask of resource elements for pilotless transmissions; a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols different from a second transmission power for transmitting data symbols; a request to use a first code rate for generating data symbols acting as virtual pilot symbols different from a second code rate for generating data symbols; or a request to use a first modulation order for generating data symbols acting as virtual pilot symbols different from a second modulation order for generating data symbols.

[0014] The mask of resource elements for pilotless transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols.

[0015] The resource elements muted may be based on resource elements mapped to pilot symbols in a mask of resource elements for pilot-based transmissions and/or resource elements mapped to data symbols acting as virtual pilot symbols in another mask of resource elements for pilotless transmissions.

[0016] At least one of the size or the pattern of the mask of resource elements for pilotless transmissions may be based on a number of apparatus performing pilot-based transmissions to the base station.

[0017] The mask of resource elements for pilotless transmissions may not indicate resource elements muted.

[0018] The means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: means for generating data symbols acting as virtual pilot symbols using the first code rate or first modulation order; means for generating data symbols using the second code rate or second modulation order; and means for transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

[0019] The means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: means for setting a transmission power for data symbols acting as virtual pilot symbols based on the first transmission power; means for setting a transmission power for data symbols based on the second transmission power; and means for transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

[0020] The means for receiving, from the base station, configuration information based on the capability information may comprise: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicates at least one of: a specific data symbol value; a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value; or an index of a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value.

[0021] The capability information may indicate a capability to support pilot-based transmissions.

[0022] The means for receiving, from the base station, configuration information based on the capability information may comprise: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one of: a request to perform pilot-based transmissions a mask of resource elements for pilot-based transmissions; an index of a mask of resource elements for pilot-based transmissions; or a request to use a first transmission power for transmitting pilot symbols different from a second transmission power for transmitting data symbols.

[0023] The mask of resource elements for pilot-based transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to pilot symbols.

[0024] The resource elements muted may be based on resource elements mapped to data symbols acting as pilot symbols in a mask of resource elements for pilot-less transmissions or mapped to pilot symbols in a mask of resource elements for pilot-based transmissions.

[0025] At least one of the size or the pattern of the mask of resource elements for pilot-based transmissions may be based on a number of apparatus performing pilotless transmissions to the base station.

[0026] The capability information may indicate a capability to support pilotless transmissions.

[0027] The means for receiving, from the base station, configuration information based on the capability information may comprise: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one of: a request to perform hybrid pilotless transmissions and pilot-based transmissions; a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions; or an index of a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions.

[0028] The mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; resource elements mapped to data symbols acting as virtual pilot symbols; or resource elements mapped to pilot symbols.

[0029] The resource elements muted may be based on resource elements mapped to pilot symbols in a mask of resource elements for pilot-based transmissions.

[0030] is At least one of the size or the pattern of the mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions may be based on a number of apparatus performing pilot-based transmissions to the base station.

[0031] The configuration information may be received via radio resource control, downlink zo control information or medium access control control element.

[0032] The configuration information may be received in a scheduling grant.

[0033] According to an aspect there is provided a method comprising: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; receiving, from the base station, configuration information based on the capability information; and transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0034] The capability information may indicate a capability to support pilotless transmissions.

[0035] The method may comprise: transmitting, to the base station, configuration information indicating at least one of: a mask of resource elements for pilotless transmissions; an index of a mask of resource elements for pilotless transmissions; or a configuration parameter to reconstruct a mask of resource elements for pilotless transmissions.

[0036] Generating data symbols may comprise: encoding data bits to generate encoded data bits; modulating some of encoded bits to generate data symbols; modulating other of the encoded data bits to generate data symbols acting as virtual pilot symbols.

[0037] The configuration information may indicate at least one of: a request to perform pilotless transmissions; a mask of resource elements for pilotless transmissions; an index of mask of resource elements for pilotless transmissions; a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols different from a second transmission power for transmitting data symbols; a request to use a first code rate for generating data symbols acting as virtual pilot symbols different from a second code rate for generating data symbols; or a request to use a first modulation order for generating data symbols acting as virtual pilot symbols different from a second modulation order for generating data symbols.

[0038] The mask of resource elements for pilotless transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols.

[0039] The resource elements muted may be based on resource elements mapped to pilot symbols in a mask of resource elements for pilot-based transmissions and/or resource elements mapped to data symbols acting as virtual pilot symbols in another mask of resource elements for pilotless transmissions.

[0040] At least one of the size or the pattern of the mask of resource elements for pilotless 30 transmissions may be based on a number of apparatus performing pilot-based transmissions to the base station.

[0041] The mask of resource elements for pilotless transmissions may not indicate resource elements muted.

[0042] The transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: generating data symbols acting as virtual pilot symbols using the first code rate or first modulation order; generating data symbols using the second code rate or second modulation order; and means for transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

[0043] The transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: setting a transmission power for data symbols acting as virtual pilot symbols based on the first transmission power; setting a transmission power for data symbols based on the second transmission power; and transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

[0044] The receiving, from the base station, configuration information based on the capability information may comprise: receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicates at least one of: a specific data symbol value; a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value; or an index of a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value.

[0045] The capability information may indicate a capability to support pilot-based transmissions The receiving, from the base station, configuration information based on the capability information may comprise: receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one of: a request to perform pilot-based transmissions a mask of resource elements for pilot-based transmissions; an index of a mask of resource elements for pilot-based transmissions; or a request to use a first transmission power for transmitting pilot symbols different from a second transmission power for transmitting data symbols.

[0046] The mask of resource elements for pilot-based transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to pilot symbols.

[0047] The resource elements muted may be based on resource elements mapped to data symbols acting as pilot symbols in a mask of resource elements for pilot-less transmissions or mapped to pilot symbols in a mask of resource elements for pilot-based transmissions.

[0048] is At least one of the size or the pattern of the mask of resource elements for pilot-based transmissions may be based on a number of apparatus performing pilotless transmissions to the base station.

[0049] The capability information may indicate a capability to support pilotless transmissions.

[0050] The receiving, from the base station, configuration information based on the capability information may comprise: receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one of: a request to perform hybrid pilotless transmissions and pilot-based transmissions; a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions; or an index of a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions.

[0051] The mask of resource elements for hybrid pilotless transmissions and pilot-based 30 transmissions may indicate at least one of: resource elements muted; resource elements mapped to data symbols; resource elements mapped to data symbols acting as virtual pilot symbols; or resource elements mapped to pilot symbols.

[0052] The resource elements muted may be based on resource elements mapped to pilot symbols in a mask of resource elements for pilot-based transmissions.

[0053] At least one of the size or the pattern of the mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions may be based on a number of apparatus performing pilot-based transmissions to the base station.

[0054] The configuration information may be received via radio resource control, downlink control information or medium access control control element.

[0055] The configuration information may be received in a scheduling grant.

[0056] According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; receiving, from the base station, configuration information based on the capability information; and transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0057] According to an aspect there is provided an apparatus comprising circuitry configured to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; receiving, from the base station, configuration information based on the capability information; and transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0058] According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; receiving, from the base station, configuration information based on the capability information; and transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0059] According to an aspect there is provided an apparatus comprising: means for receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; means for transmitting, to the user equipment, configuration information based on the capability information; means for receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and means for determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0060] The means for receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: means for receiving, from the user equipment, pilotless transmissions based on the configuration information; and wherein the means for determining a channel response based on the pilotless transmissions or pilot-based transmissions comprises: means for demodulating and decoding data symbols acting as virtual pilot symbols based on the configuration information; and means for determining the channel response based on the demodulated and decoded data symbols acting as virtual pilot symbols.

[0061] The extracted data symbols acting as virtual pilot symbols may comprise complex-valued symbols The means for receiving, from the user equipment, pilotless transmissions or pilot-30 based transmissions based on the configuration information may comprise: means for receiving, from the user equipment, pilot-based transmissions based on the configuration information; and wherein the means for determining a channel response based on the pilotless transmissions or pilot-based transmissions may comprise: means for extracting pilot symbols based on the configuration information; and means for determining the channel response based on the extracted pilot symbols.

[0062] The means for determining the channel response based on the extracted data symbols acting as virtual pilot symbols may comprise: means for providing the extracted data symbols acting as virtual pilot symbols to a channel estimator as an input to obtain the channel response as an output; or wherein the means for determining the channel response based on the extracted pilot symbols may comprise: means for providing the extracted pilot symbols to a channel estimator as an input to obtain the channel response as an output.

[0063] The channel estimator may comprise a deep neural network trained to output a channel response.

[0064] The deep neural network may be provided at least one of extracted data symbols, extracted data symbols acting as virtual pilot symbols, noise or signal to noise ratio as an input.

[0065] The channel estimator may comprise a deep neural network trained to output a channel response.

[0066] The deep neural network may be provided at least one of extracted data symbols, extracted pilot symbols, noise or signal to noise ratio as an input.

[0067] The apparatus may comprise: means for attempting to demodulate and decode data symbols acting as virtual pilot symbols to generate first encoded sequences of bits using a first code rate or first modulation order; means for attempting to demodulate and decode data symbols acting as virtual pilot symbols using the second code rate or second modulation order.

[0068] The apparatus may comprise: means for successfully demodulating and decoding data symbols acting as virtual pilot symbols using the first code rate or first modulation order; means for unsuccessfully demodulating and decoding data symbols using the second code rate; and means for re-attempting to decode and decode data symbols using the second code rate taking into consideration the data symbols acting as virtual pilot symbols.

[0069] The apparatus may comprise: means for updating a counter value in response to unsuccessfully demodulating and decoding the data symbols using the second code rate or second modulation order; and means for re-attempting to decode and decode the data symbols using the second code rate or second modulation order taking into consideration the data symbols acting as virtual pilot symbols, unless the counter value has not reached a threshold.

[0070] The apparatus may comprise: means for transmitting, to the user equipment, a request to re-transmit the pilotless transmissions, if the counter value has reached the threshold.

[0071] According to an aspect there is provided a method comprising: receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; transmitting, to the user equipment, configuration information based on the capability information; receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0072] The receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: receiving, from the user equipment, pilotless transmissions based on the configuration information; and wherein the determining a channel response based on the pilotless transmissions or pilot-based transmissions comprises: demodulating and decoding data symbols acting as virtual pilot symbols based on the configuration information; and determining the channel response based on the demodulated and decoded data symbols acting as virtual pilot symbols.

[0073] The extracted data symbols acting as virtual pilot symbols may comprise complex-valued symbols The receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information may comprise: receiving, from the user equipment, pilot-based transmissions based on the configuration information; and wherein the determining a channel response based on the pilotless transmissions or pilot-based transmissions may comprise: extracting pilot symbols based on the configuration information; and determining the channel response based on the extracted pilot symbols.

[0074] The determining the channel response based on the extracted data symbols acting as virtual pilot symbols may comprise: providing the extracted data symbols acting as virtual pilot symbols to a channel estimator as an input to obtain the channel response as an output; or wherein the determining the channel response based on the extracted pilot symbols may comprise: providing the extracted pilot symbols to a channel estimator as an input to obtain the channel response as an output.

[0075] The channel estimator may comprise a deep neural network trained to output a channel response.

[0076] The deep neural network may be provided at least one of extracted data symbols, extracted data symbols acting as virtual pilot symbols, noise or signal to noise ratio as an input.

[0077] The channel estimator may comprise a deep neural network trained to output a channel response.

[0078] The deep neural network may be provided at least one of extracted data symbols, extracted pilot symbols, noise or signal to noise ratio as an input.

[0079] The method may comprise: attempting to demodulate and decode data symbols acting as virtual pilot symbols to generate first encoded sequences of bits using a first code rate or first modulation order; attempting to demodulate and decode data symbols acting as virtual pilot symbols using the second code rate or second modulation order.

[0080] The method may comprise: successfully demodulating and decoding data symbols acting as virtual pilot symbols using the first code rate or first modulation order; unsuccessfully demodulating and decoding data symbols using the second code rate; and re-attempting to decode and decode data symbols using the second code rate taking into consideration the data symbols acting as virtual pilot symbols.

[0081] The method may comprise: updating a counter value in response to unsuccessfully demodulating and decoding the data symbols using the second code rate or second modulation order; and re-attempting to decode and decode the data symbols using the second code rate or second modulation order taking into consideration the data symbols acting as virtual pilot symbols, unless the counter value has not reached a threshold.

[0082] The method may comprise: transmitting, to the user equipment, a request to retransmit the pilotless transmissions, if the counter value has reached the threshold.

[0083] According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; transmitting, to the user equipment, configuration information based on the capability information; receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0084] According to an aspect there is provided an apparatus comprising circuitry configured to perform: receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; transmitting, to the user equipment, configuration information based on the capability information; receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0085] According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; transmitting, to the user equipment, configuration information based on the capability information; receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0086] According to an aspect there is provided an apparatus comprising: means for transmitting, to a base station, capability information indicating a capability to support pilotless transmissions; means for receiving, from the base station, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; means for receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and means for transmitting, to the base station, transmissions based on the first configuration information and the second configuration.

[0087] The mask of resource elements for transmissions may be a mask of resource elements for pilotless transmissions and the transmissions may be pilotless transmissions; or the mask of resource elements for transmissions may be a mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions and the transmissions may be hybrid pilotless transmissions and pilot-based transmissions.

[0088] The mask of resource elements for pilot-based transmissions may comprise at least one of: resource elements to be muted; resource elements mapped to data symbols; or resource elements mapped to pilot symbols.

[0089] The means for transmitting, to the base station, transmissions based on the first configuration information and the second configuration may comprise: means for determining a mask of resource elements for transmissions based on the first configuration information and the second configuration; and means for transmitting, to the base station, transmissions based on the mask of resource elements for transmissions.

[0090] The mask of resource elements for pilotless transmissions may comprise at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols; or the mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions may comprise at least one of: resource elements muted; resource elements mapped to data symbols; resource elements mapped to data symbols acting as virtual pilot symbols; or resource elements mapped to pilot symbols.

[0091] The means for receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: means for receiving, from the base station, second configuration information indicating 5 that resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions when at least one other apparatus supporting pilot-based transmissions is in a cell provided by the base station and uses 10 the mask of resource elements for pilot-based transmissions.

[0092] The means for receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: means for receiving, from the base station, second configuration information indicating that resource elements mapped to pilot symbols within the mask of resource elements for pilot-based transmissions are to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for pilotless transmissions when another apparatus supporting pilot-based transmissions is not in a cell provided by the base station or does not use the mask of resource elements for pilot-based transmissions.

[0093] The apparatus may comprise: means for receiving, from the base station, third configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and means for transmitting, to the base station, transmissions based on the first configuration information, the second configuration information and the third configuration information.

[0094] The first configuration information may indicate that the mask of resource elements for pilot-based transmissions is for information for the apparatus.

[0095] The second configuration information or the third configuration information may indicate: a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols; or an index of a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols, a configuration parameter to build a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols, where the resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols within the mask for transmissions correspond to some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions.

[0096] The mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols may be indicated with at least one of: an index of a resource element to be muted, to be mapped to a data symbol or to be mapped to a data symbols acting as a virtual pilot symbol; a density in time of resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols; or a density in frequency of resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols.

[0097] The first configuration information may be received via radio resource control, downlink control information or medium access control control element.

[0098] The second configuration information may be received via radio resource control, downlink control information or medium access control control element.

[0099] The third configuration information may be received via downlink control information or medium access control control element.

[0100] According to an aspect there is provided a method comprising: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions; receiving, from the base station, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and transmitting, to the base station, transmissions based on the first configuration information and the second configuration.

[0101] The mask of resource elements for transmissions may be a mask of resource elements for pilotless transmissions and the transmissions may be pilotless transmissions; or the mask of resource elements for transmissions may be a mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions and the transmissions may be hybrid pilotless transmissions and pilot-based transmissions.

[0102] The mask of resource elements for pilot-based transmissions may comprise at least one of: resource elements to be muted; resource elements mapped to data symbols; or resource elements mapped to pilot symbols.

[0103] The transmitting, to the base station, transmissions based on the first configuration information and the second configuration may comprise: determining a mask of resource elements for transmissions based on the first configuration information and the second configuration; and transmitting, to the base station, transmissions based on the mask of resource elements for transmissions.

[0104] The mask of resource elements for pilotless transmissions may comprise at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols; or the mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions may comprise at least one of: resource elements muted; resource elements mapped to data symbols; resource elements mapped to data symbols acting as virtual pilot symbols; or resource elements mapped to pilot symbols.

[0105] The receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: receiving, from the base station, second configuration information indicating that resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions when at least one other apparatus supporting pilot-based transmissions is in a cell provided by the base station and uses the mask of resource elements for pilot-based transmissions.

[0106] The receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: receiving, from the base station, second configuration information indicating that resource elements mapped to pilot symbols within the mask of resource elements for pilot-based transmissions are to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for pilotless transmissions when another apparatus supporting pilot-based transmissions is not in a cell provided by the base station or does not use the mask of resource elements for pilot-based transmissions.

[0107] The method may comprise: receiving, from the base station, third configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and transmitting, to the base station, transmissions based on the first configuration information, the second configuration information and the third configuration information.

[0108] The first configuration information may indicate that the mask of resource elements for pilot-based transmissions is for information for the apparatus.

[0109] The second configuration information or the third configuration information may indicate: a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols; or an index of a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols, a configuration parameter to build a mask for transmissions indicating resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols, where the resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols within the mask for transmissions correspond to some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions.

[0110] The mask for transmissions indicating resource elements to be muted, to be mapped 30 to data symbols or to be mapped to data symbols acting as virtual pilot symbols may be indicated with at least one of: an index of a resource element to be muted, to be mapped to a data symbol or to be mapped to a data symbols acting as a virtual pilot symbol, a density in time of resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols; or a density in frequency of resource elements to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols.

[0111] The first configuration information may be received via radio resource control, downlink control information or medium access control control element.

[0112] The second configuration information may be received via radio resource control, downlink control information or medium access control control element.

[0113] The third configuration information may be received via downlink control information or medium access control control element.

[0114] According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions; receiving, from the base station, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and transmitting, to the base station, transmissions based on the first configuration information and the second configuration.

[0115] According to an aspect there is provided an apparatus comprising circuitry configured to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions; receiving, from the base station, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and transmitting, to the base station, transmissions based on the first configuration information and the second configuration.

[0116] According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions; receiving, from the base station, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; receiving, from the base station, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and transmitting, to the base station, transmissions based on the first configuration information and the second configuration.

[0117] According to an aspect there is provided an apparatus comprising: means for receiving, from a user equipment, capability information indicating a capability to support pilotless transmissions; means for transmitting, to the user equipment, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; means for transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and means for receiving, from the user equipment, transmissions based on the first configuration information and the second configuration.

[0118] The means for transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: means for detecting that another apparatus supporting pilot-based transmissions is in a cell provided by the apparatus and uses the mask of resource elements for pilot-based transmissions; and means for transmitting, to the user equipment, second configuration information indicating that some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions.

[0119] The means for transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols may comprise: means for detecting that another apparatus supporting pilot-based transmissions is not in a cell provided by the apparatus or does not use the mask of resource elements for pilot-based transmissions; and means for transmitting, to the user equipment, second configuration information indicating that some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions.

[0120] According to an aspect there is provided a method comprising: receiving, from a user equipment, capability information indicating a capability to support pilotless transmissions; transmitting, to the user equipment, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and receiving, from the user equipment, transmissions based on the first configuration information and the second configuration.

[0121] The transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions may comprise: detecting that another apparatus supporting pilot-based transmissions is in a cell provided by the apparatus and uses the mask of resource elements for pilot-based transmissions; and transmitting, to the user equipment, second configuration information indicating that some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions.

[0122] The transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols may comprise: detecting that another apparatus supporting pilot-based transmissions is not in a cell provided by the apparatus or does not use the mask of resource elements for pilot-based transmissions; and transmitting, to the user equipment, second configuration information indicating that some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in the mask of resource elements for transmissions.

[0123] According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving, from a user equipment, capability information indicating a capability to support pilotless transmissions; transmitting, to the user equipment, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and receiving, from the user equipment, transmissions based on the first configuration information and the second configuration.

[0124] According to an aspect there is provided an apparatus comprising circuitry configured to perform: receiving, from a user equipment, capability information indicating a capability to support pilotless transmissions; transmitting, to the user equipment, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and receiving, from the user equipment, transmissions based on the first configuration information and the second configuration.

[0125] According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: receiving, from a user equipment, capability information indicating a capability to support pilotless transmissions; transmitting, to the user equipment, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions; transmitting, to the user equipment, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions; and receiving, from the user equipment, transmissions based on the first configuration information and the second configuration.

[0126] According to an aspect, there is provided a computer readable medium comprising program instructions stored thereon for performing at least one of the above methods.

[0127] According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least one of the 20 above methods.

[0128] According to an aspect, there is provided a non-volatile tangible memory medium comprising program instructions stored thereon for performing at least one of the above methods.

[0129] In the above, many different aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above.

[0130] Various other aspects are also described in the following detailed description and in the attached claims.

[0131] List of abbreviations AF: Application Function AMF: Access and Mobility Management Function BPSK: Binary Phase Shift Keying BS: Base Station CDM: Code Division Multiplexing CE: Control Element CRC: Cyclic Redundancy Check CU: Centralized Unit DCI: Downlink Control Information DFT: Digital Fourier Transform DL: Downlink DU: Distributed Unit gNB: gNodeB IDFT: Inverse Digital Fourier Transform loT: Internet of Things LTE: Long Term Evolution MCS: Modulation and Coding Scheme MS: Mobile Station MTC: Machine Type Communication NEF: Network Exposure Function NF: Network Function NR: New radio NRF: Network Repository Function OFDM: Orthogonal Frequency Division Multiplexing PUSCH: Physical Uplink Shared Channel QAM: Quadrature Amplitude Modulation RAM: Random Access Memory (R)AN: (Radio) Access Network RE: Resource Element ROM: Read Only Memory RRC: Radio Resource Control SMF: Session Management Function SNR: Signal to Noise Ratio UE: User Equipment 4G: 4th Generation 5G: 5th Generation 5GC: 5G Core network 5G5: 5G System 6G: 6th Generation

[0132] Brief Description of the Figures

[0133] Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which: Fig. 1 shows a schematic representation of an example 5G system; Fig. 2 shows a schematic representation of an example control apparatus; Fig. 3 shows a schematic representation of an example user equipment; Fig. 4 shows a signalling diagram of an example of a process for managing pilotless transmissions or pilot-based transmissions in a communication system; Fig. 5 shows a schematic representation of an example of a resource grid for pilotless transmissions and a resource grid for pilot-based transmissions in a communication system; Fig. 6 shows a signalling diagram of an example of a process for managing pilotless transmissions or pilot-based transmissions in a communication system, Fig. 7 shows a signalling diagram of an example of a base station managing pilotless transmissions or pilot-based transmissions in a communication system; Fig. 8 shows a schematic representation of a transmission chain of a user equipment, Fig. 9 shows a schematic representation of a reception chain of a base station; Fig. 10 shows a schematic representation of examples of a resource grid for pilotless transmissions in a communication system; Fig. 11 shows a schematic representation of an example of a modulation block and a mapping block of a transmission chain of a user equipment and an example of a resource grid for pilotless transmissions in a communication system; Fig. 12 shows a schematic representation of a transmission chain of a user equipment and a reception chain of a base station; Fig. 13 shows a schematic representation of examples of resource grids for pilotless transmissions and examples of resource grids for pilot-based transmissions in a 20 Communication system; Fig. 14 shows a schematic representation of examples of resource grids for hybrid pilotless and pilot-based transmissions and examples of resource grids for pilot-based transmissions in a communication system; Fig. 15 shows a schematic representation of examples of resource grids for pilotless transmissions and examples of resource grids for pilot-based transmissions in a communication system; Fig. 16 shows a block diagram of an example of method for managing pilotless transmissions or pilot-based transmissions in a communication system; Fig. 17 shows a block diagram of an example of method for managing pilotless transmissions or pilot-based transmissions in a communication system; Fig. 18 shows a block diagram of an example of method for managing pilotless 5 transmissions in a communication system; Fig. 19 shows a block diagram of an example of method for managing pilotless transmissions in a communication system; and Fig. 20 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the method of Fig. 16 to Fig.19.

[0134] Detailed Description of the Figures

[0135] In the following certain embodiments are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the exemplifying embodiments, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Fig. 1, Fig.2 and Fig.3 to assist in understanding the technology underlying the described examples.

[0136] FIG. 1 shows a schematic representation of an example of a 5G system (5GS). The 5GS may comprises user equipment (UEs), a (radio) access network ((R)AN), a 5G 25 core network (5GC), one or more application functions (AF) and one or more data networks (DN).

[0137] The 5G (R)AN may comprise one or more gNodeBs (gNBs). The gNodeBs may comprise one or more gNB distributed unit functions connected to one or more gNB centralized unit functions.

[0138] The gNodeBs may comprise activator gNodeBs, reader gNodeBs or activator and reader gNodeBs.

[0139] The 5GC may comprise an access and mobility management function (AMF), a session management function (SMF), an authentication server function (AUSF), a user data management (UDM), a user plane function (UPF), a network exposure function (NEF).

[0140] Fig. 2 illustrates an example of a control apparatus 200 for controlling a function of the (R)AN or the 5GC as illustrated on Fig. 1. The control apparatus may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and an input/output interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects. The software code 215 may be stored in the ROM 211b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5G (R)AN or the 5GC. In some embodiments, each function of the (R)AN or the 5GC comprises a control apparatus 200. In alternative embodiments, two or more functions of the (R)AN or the 5GC may share a control apparatus.

[0141] Fig. 3 illustrates an example of a user equipment 300, such as the terminal illustrated on Fig. 1. The UE 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a 'smart phone', a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like. The UE 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

[0142] The UE 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Fig. 3 transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0143] The UE 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a.

[0144] The processor, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device.

[0145] One or more aspect of this disclosure relates to managing pilotless transmissions and pilot-based transmissions between a UE and a gNB. For example, the gNB may be a 6G gNB and the UE may be a 4G UE, 5G UE or a 6G UE.

[0146] It will be understood that although the above concepts have been discussed in the context of 4G, 5G and 6G, one or more of these concepts may be applied to other generations of cellular systems.

[0147] In this disclosure, pilotless transmissions may refer to UL transmissions without pilots.

[0148] In this disclosure, pilot-based transmissions may refer to UL transmissions with pilots.

[0149] In this disclosure, a pilot may refer to a demodulation reference signal (DM-RS).

[0150] To enable a UE vendor or UE implementation agnostic UL receiver architecture, a gNB should be able to successfully equalize a channel between a UE and the gNB and demodulate and decode UL data from the UE. The UE may support pilotless transmissions or pilot-based transmissions. The UE may support different patterns of resource elements (REs) mapped to pilots (e.g., in a time domain, in a frequency domain or in a space domain).

[0151] Fig. 4 shows a signalling diagram of an example of a process for managing pilotless transmissions or pilot-based transmissions in a communication system.

[0152] Initially, a UE1 may be in a radio resource control (RRC) disconnected mode (e.g., idle mode).

[0153] At step 1, the UE1 may transmit, to a gNB, capability information. The capability information may indicate a capability to support pilotless transmissions. The gNB may include the UE1 in a set Si of UEs supporting pilotless transmissions.

[0154] The UE1 may transmit, to the gNB, configuration information. The configuration information may comprise at least one configuration parameter to reconstruct a mask of resource elements for pilotless transmissions. The configuration information may indicate a mask of REs for pilotless transmissions. The configuration may indicate an index of a mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions. The table of masks of REs for pilotless transmissions may be stored at the UE1 and the gNB. A mask of REs for pilotless transmissions may indicate REs muted. The mask of resource elements for pilotless transmissions may indicate REs mapped to data symbols. The mask of REs for pilotless transmissions may indicate REs mapped to data symbols acting as virtual pilot symbols.

[0155] The mask of REs for pilotless transmissions may indicate an index of a RE to be muted, a density of REs to be muted in time domain and/or a density of REs to be muted in frequency domain.

[0156] The mask of REs for pilotless transmissions may indicate an index of a RE mapped to a data symbol, a density of REs mapped to data symbols in time domain and/or a density of REs mapped to data symbols in frequency domain.

[0157] The mask of REs for pilotless transmissions may indicate an index of a RE mapped to a data symbol acting as a virtual pilot symbol, a density of REs mapped to data symbols acting as virtual pilot symbols in time domain and/or a density of REs mapped to data symbols acting as virtual pilot symbols in frequency domain.

[0158] In this disclosure, the expressions "mask" or "pattern" may be used interchangeably.

[0159] In this disclosure, the expressions "data symbols" or "data symbols acting as virtual pilot symbols" may refer to complex-valued symbols. The "data symbols" or "data symbols acting as virtual pilot symbols" may convey data on physical uplink shared channel (PUSCH).

[0160] In this disclosure, the expressions "virtual pilot" and "data pilot" may be used interchangeably. The expressions "virtual pilot symbols" and "data pilot symbols" may be used interchangeably.

[0161] Generating data symbols may comprise receiving bits, encoding the bits to generate encoded bits, modulating some the encoded bits to generate data symbols and modulating other of the encoded bits to generate data symbols acting as virtual pilot symbols.

[0162] At step 2, the gNB may transmit, to the UE, configuration information. The gNB may transmit, to the UE, configuration information via RRC signalling. The configuration information may comprise a request to perform pilotless transmissions (e.g., a variable "DMRS TRANSMISSION SCHEME" may be set to "PILOTLESS").

[0163] The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions.

[0164] The configuration information may comprise a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols different from (e.g., higher than) a second transmission power for transmitting data symbols. The first transmission power may be different from (e.g., higher than) the second transmission power by a scaling factor The scaling factor can received via RRC signaling, via MAC CE or via DCI.

[0165] The configuration information may comprise a request to use a first code rate or a first modulation order for generating data symbols acting as virtual pilot symbols different from (e.g., lower than) a second code rate or a second modulation order for generating data symbols. As a result, a modulation and coding (MCS) scheme for generating data symbols acting as virtual pilot symbols is more robust than a MCS scheme for generating data symbols.

[0166] At step 3, the UE1 may transmit, to the gNB, configuration information.

[0167] The UE1 may switch from the RRC disconnected mode (e.g., idle mode) to the RRC 30 connected mode.

[0168] At step 4, the gNB may transmit, to the UE, a scheduling grant (e.g. UL grant on physical uplink shared channel). The gNB may transmit, to the UE1, configuration information. The gNB may transmit, to the UE1, the scheduling grant and/or the configuration information via downlink control information (DCI). The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions.

[0169] At step 5, the UE1 may determine a mask of REs for pilotless transmissions based on the configuration information. The UE1 may encode and modulate data bits based on the configuration information to generate data symbols and data symbols acting as pilot symbols. The UE1 may map data symbols and data symbols acting as pilot symbols to REs in a resource grid based on the configuration information. The UE1 may apply OFDM modulation. OFDM modulation may include inverse digital Fourier transformation (IDFT).

[0170] At step 6, the UE1 may transmit, to the gNB, the pilotless transmissions over a first channel between the UE1 and the gNB.

[0171] At step 7, the gNB may receive the pilotless transmissions over the first channel. The gNB may apply OFDM demodulation. OFDM demodulation may include digital Fourier transformation (DFT). The gNB may extract the data symbols and the data symbols acting as pilot symbols based on the configuration information. The gNB may demodulate and decode the data symbols and data symbols acting as pilot symbols to generate data bits. The gNB may provide the data symbols acting as pilot symbols to a channel estimator as an input to provide a channel response as an output. The channel estimator may comprise a deep neural network trained to output a channel response when provided data symbols acting as virtual pilot symbols as an input.

[0172] At step 8, the UE2 may be in a RRC disconnected mode (e.g., idle mode). The UE2 may transmit, to a gNB, capability information. The capability information may indicate a capability to support pilot-based transmissions. The gNB may include the UE2 in a set S2 of UEs supporting pilot-based transmissions.

[0173] The UE2 may transmit, to the gNB, configuration information. The configuration information may comprise at least one configuration parameter to reconstruct a mask of resource elements for pilot-based transmissions. The configuration information may indicate a mask of REs for pilot-based transmissions. The configuration may indicate an index of a mask of REs for pilot-based transmissions within a table of masks of REs for pilot-based transmissions. The table of masks of REs for pilot-based transmissions may be stored at the UE2 and the gNB. A mask of REs for pilot-based transmissions may indicate REs muted. The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilot-less transmissions of another UE in Si to avoid interference. The REs muted may corresponds to REs mapped to pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference. The mask of resource elements for pilot-based transmissions may indicate REs mapped to data symbols. The mask of REs for pilot-based transmissions may indicate REs mapped to pilot symbols.

[0174] The mask of REs for pilot-based transmissions may indicate an index of a RE to be muted, a density of REs to be muted in time domain and/or a density of REs to be muted in frequency domain.

[0175] The mask of REs for pilot-based transmissions may indicate an index of a RE mapped 25 to a data symbol, a density of REs mapped to data symbols in time domain and/or a density of REs mapped to data symbols in frequency domain.

[0176] The mask of REs for pilot-based transmissions may indicate an index of a RE mapped to a pilot symbol, a density of REs mapped to pilot symbols in time domain and/or a density of REs mapped to virtual pilot symbols in frequency domain.

[0177] In this disclosure, the expression "pilot symbols" may refer to complex-valued symbols.

[0178] At step 9, the gNB may transmit, to the UE, configuration information. The gNB may transmit, to the UE, configuration information via RRC signalling. The configuration information may comprise a request to perform pilot-based transmissions (e.g., a variable "DMRS TRANSMISSION SCHEME" may be set to "PILOT-BASED").

[0179] The configuration information may comprise a mask of REs for pilot-based transmissions or an index of mask of REs for pilot-based transmissions within a table of masks of REs for pilotless transmissions.

[0180] The mask of REs for pilot-based transmissions may indicate REs muted. The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilotless transmissions the UE1 in Si or REs mapped to pilot symbols in another mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference.

[0181] The configuration information may comprise a request to use a first transmission power for transmitting pilot symbols different from (e.g., higher than) a second transmission power for transmitting data symbols. The first transmission power may be different from (e.g., higher than) the second transmission power by a scaling factor The scaling factor can received via RRC signaling, via MAC CE or via DCI.

[0182] The UE2 may switch from the radio resource control disconnected mode (e.g., idle mode) to the RRC connected mode.

[0183] At step 10, the gNB may transmit, to the UE1, configuration information. The gNB may transmit, to the UE1, configuration information via RRC signaling or medium access control (MAC) control element (CE). The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions. The mask of REs for pilotless transmissions may indicate REs muted. The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S1to avoid interference. The REs muted may corresponds to REs mapped to pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference.

[0184] At step 11, the gNB may transmit, to the UE1, a scheduling grant (e.g. UL grant on physical uplink shared channel). The gNB may transmit, to the UE1, configuration information. The gNB may transmit, to the UE1, the scheduling grant and/or the configuration information via DCI. The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions.

[0185] At step 12, the gNB may transmit, to the UE2, a scheduling grant (e.g. UL grant on physical uplink shared channel). The gNB may transmit, to the U2E, the scheduling grant via DCI.

[0186] At step 13, the UE1 may determine a mask of REs for pilotless transmissions based on configuration information. The UE1 may encode and modulate data bits based on configuration information to generate data symbols and data symbols acting as pilot symbols. The UE1 may map data symbols and data symbols acting as pilot symbols to REs in a resource grid based on the configuration information. The UE1 may apply OFDM modulation. OFDM modulation may include IDFT.

[0187] At step 14, the UE2 may determine a mask of REs for pilot-based transmissions based on configuration information. The UE2 may encode and modulate data bits based on configuration information to generate data symbols and data symbols acting as pilot symbols. The UE2 may map data symbols and data symbols acting as pilot symbols to REs in a resource grid based on the configuration information. The UE2 may apply OFDM modulation. OFDM modulation may include IDFT.

[0188] At step 15, the UE1 may transmit, to the gNB, the pilotless transmissions over the first channel between the UE1 and the gNB.

[0189] At step 16, the UE2 may transmit, to the gNB, the pilot-based transmissions over a second channel between the UE2 and the gNB.

[0190] At step 17, the gNB may receive the pilotless transmissions over the first channel. The 5 gNB may apply OFDM demodulation. OFDM demodulation may include DFT. The gNB may extract the data symbols and the data symbols acting as pilot symbols based on configuration information. The gNB may demodulate and decode the data symbols and data symbols acting as pilot symbols to generate data bits. The gNB may provide the data symbols acting as pilot symbols to a channel estimator as an input to provide 10 a channel response as an output. The channel estimator may comprise a deep neural network trained to output a channel response. The deep neural network may be provided data symbols, data symbols acting as virtual pilot symbols, noise or signal to noise ratio as an input.

[0191] The gNB may receive the pilot-based transmissions over the first channel. The gNB may apply OFDM demodulation. OFDM demodulation may include DFT. The gNB may extract the data symbols and pilot symbols based on configuration information. The gNB may demodulate and decode the data symbols to generate data bits. The gNB may provide the pilot symbols to a channel estimator as an input to provide a channel response as an output. The channel estimator may comprise a deep neural network trained to output a channel response. The deep neural network may be provided pilot symbols, noise or signal to noise ratio as an input.

[0192] Fig. 5 shows a schematic representation of an example of a resource grid for pilotless transmissions and a resource grid for pilot-based transmissions in a communication system. The resource grid for pilotless transmissions comprises REs muted, REs for data symbols and REs for data symbols acting as pilot symbols. The resource grid for pilot-based transmissions comprises REs muted, REs for data symbols and REs for pilot symbols.

[0193] Fig. 6 shows a signalling diagram of an example of a process for managing pilotless transmissions or pilot-based transmissions in a communication system.

[0194] The UE1 may transmit, to a gNB, capability information. The capability information may indicate a capability to support pilotless transmissions. The gNB may include the UE1 in the set Si of UEs supporting pilotless transmissions.

[0195] The gNB may transmit, to the UE1, configuration information. The gNB may transmit, to the UE1, configuration information via RRC signalling.

[0196] In a first alternative, the configuration information may comprise a request to perform pilotless transmissions (e.g., a variable "DMRSTRANSMISSION_SCHEME" may be set to "PILOTLESS").

[0197] The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilotless transmissions within a table of masks of REs for pilotless transmissions. A mask of REs for pilotless transmissions may indicate REs muted. The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilot-less transmissions of another UE in Si to avoid interference. The REs muted may corresponds to REs mapped to pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference. The mask of REs for pilotless transmissions may indicate REs mapped to data symbols. The mask of REs for pilotless transmissions may indicate REs mapped to data symbols acting as virtual pilot symbols. The mask of REs for pilotless transmissions may indicate REs mapped to pilot symbols.

[0198] The configuration information may comprise a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols different from (e.g., higher than) a second transmission power for transmitting data symbols.

[0199] The configuration information may comprise a request to use a first code rate or first modulation order for generating data symbols acting as virtual pilot symbols different from (e.g., lower than) a second code rate or second modulation order for generating data symbols.

[0200] The size and/or the pattern of the mask of REs for pilotless transmissions may be based on a number and/or capabilities of UEs in Si. The size and/or the pattern of the mask of REs for pilotless transmissions may be based on a number and/or capabilities of UEs in S2.

[0201] In a second alternative, the configuration information may comprise a request to perform hybrid pilotless transmissions and pilot-based transmissions (e.g., a variable "DMRS TRANSMISSION SCHEME" may be set to "HYBRID").

[0202] The configuration information may comprise a mask of REs for hybrid pilotless transmissions and pilot-based transmissions or an index of mask of REs for hybrid pilotless transmissions and pilot-based transmissions within a table of masks of REs for hybrid pilotless transmissions and pilot-based transmissions. A mask of REs for hybrid pilotless transmissions and pilot-based transmissions may indicate REs muted.

[0203] The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilot-less transmissions of another UE in Si to avoid interference. The REs muted may corresponds to REs mapped to pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference. The mask of REs for hybrid pilotless transmissions and pilot-based transmissions may indicate REs mapped to data symbols. The mask of REs for hybrid pilotless transmissions and pilot-based transmissions may indicate REs mapped to data symbols acting as virtual pilot symbols. The mask of REs for hybrid pilotless transmissions and pilot-based transmissions may indicate REs mapped to pilot symbols.

[0204] The configuration information may comprise a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols and for transmitting pilots different from (e.g., higher than) a second transmission power for transmitting 30 data symbols.

[0205] The configuration information may comprise a request to use a first code rate or first modulation order for generating data symbols acting as virtual pilot symbols and for generating pilot symbols different from (e.g., lower than) a second code rate or second modulation order for generating data symbols.

[0206] The size and/or the pattern of the mask of REs for hybrid pilotless transmissions and pilot-based transmissions may be based on a number and/or capabilities of UEs in Si. The size and/or the pattern of the mask of REs for hybrid pilotless transmissions and pilot-based transmissions may be based on a number and/or capabilities of UEs in S2.

[0207] The UE2 may transmit, to the gNB, capability information. The capability information may indicate a capability to support pilot-based transmissions. The gNB may include the UE2 in the set S2 of UEs supporting pilotless transmissions.

[0208] The gNB may transmit, to the UE2, configuration information. The gNB may transmit, to the UE2, configuration information via RRC signalling.

[0209] The configuration information may comprise a request to perform pilot-based transmissions (e.g., a variable "DMRS_TRANSMISSION_SCHEME" may be set to 20 "P I LOT-BASE").

[0210] The configuration information may comprise a mask of REs for pilotless transmissions or an index of mask of REs for pilot-based transmissions within a table of masks of REs for pilot-based transmissions. A mask of REs for pilot-based transmissions may indicate REs muted. The REs muted may corresponds to REs mapped to data symbols acting as pilot symbols in the mask of resource elements for pilot-less transmissions of another UE in Si to avoid interference. The REs muted may corresponds to REs mapped to pilot symbols in the mask of resource elements for pilot-based transmissions of another UE in S2 to avoid interference. The mask of REs for pilot-based transmissions may indicate REs mapped to data symbols. The mask of REs for pilot-based transmissions may indicate REs mapped to pilot symbols.

[0211] The size and/or the pattern of the mask of REs for pilot-based transmissions may be based on a number and/or capabilities of UEs in Si. The size and/or the pattern of the mask of REs for pilot-based transmissions may be based on a number and/or capabilities of UEs in S2.

[0212] The UE1 may transmit, to the gNB, pilotless transmissions over a first channel between the UE1 and the gNB.

[0213] The UE2 may transmit, to the gNB, pilot-based transmissions over a second channel 10 between the UE2 and the gNB.

[0214] The gNB may receive the pilotless transmissions over the first channel. The gNB may apply OFDM demodulation. OFDM demodulation may include DFT. The gNB may extract the data symbols and the data symbols acting as pilot symbols based on configuration information. The gNB may demodulate and decode the data symbols and data symbols acting as pilot symbols to generate data bits. In the first alternative, the gNB may provide the data symbols acting as pilot symbols to a channel estimator as an input to provide a channel response as an output. In the second alternative, the gNB may provide the data symbols acting as pilot symbols and pilot symbols to a channel estimator as an input to provide a channel response as an output.

[0215] The gNB may receive the pilot-based transmissions over the first channel. The gNB may apply OFDM demodulation. OFDM demodulation may include DFT. The gNB may extract the data symbols and pilot symbols based on configuration information. The gNB may demodulate and decode the data symbols to generate data bits. The gNB may provide the pilot symbols to a channel estimator as an input to provide a channel response as an output.

[0216] In some scenarios, when both the UE1 transmits pilotless transmissions and the UE2 transmits pilot-based transmissions on same time-frequency resources, the pilotless transmissions may interfere with pilot-based transmissions (e.g., data symbols or data symbols acting as pilot symbols may interfere with pilot symbols if they are mapped the same REs).

[0217] A mask of REs for pilotless transmissions to comprise muted REs corresponding to REs mapped to pilot symbols in a mask of REs for pilot-base transmissions. A mask of REs for pilot-based transmissions may comprise muted REs corresponding to REs mapped to data symbols acting as pilot symbols in a mask of REs for pilotless transmissions.

[0218] A problem may be to adjust muted REs within a mask of REs for pilotless transmissions with minimum complexity and/or signaling overhead. Another problem may be to adjust muted REs within a mask of REs for pilotless transmissions when a UE enters or leave a cell provided by the gNB? When the UE uses a mask of REs for pilot-base transmissions interfering with a mask of REs for pilotless transmissions? Fig. 7 shows a signalling diagram of an example of a base station managing pilotless transmissions or pilot-based transmissions in a communication system.

[0219] A UE included in Si may be in a cell provided by the gNB. The UE included in Si may transmit, to the gNB, capability information. The capability information may indicate a capability to support pilotless transmissions.

[0220] The gNB may transmit, to the UE included in Si, first configuration information. The first configuration information may indicate a mask of REs for pilot-based transmissions or an index of a mask of REs for pilotless transmissions (i.e., a reference).

[0221] The first configuration information may indicate that the mask of REs for pilot-based transmissions is for information only for the UE included in Si (i.e., not for use by the UE included in Si for pilot-based transmissions to the gNB). For example, the first configuration information may comprise a flag (e.g., in DMRS-UplinkConfig 1E). When the flag is set to a first value (e.g., 0), the mask of REs for pilot-based transmissions may be for information only. By contrast, when the flag is set to a second value (e.g., 1), the mask of REs for pilot-based transmissions may be for use for pilot-based transmissions to the gNB. The first configuration information may be received via RRC signaling, via DCI or via MAC CE.

[0222] It will be understood that the first configuration information may indicate more than one mask of REs for pilot-based transmissions or more than one index of mask of REs for pilotless transmissions.

[0223] The gNB may determine whether a UE included in S2 is in the cell provided by the gNB. The gNB may determine whether the UE included in 52 uses the mask of REs for pilot-base transmissions to transmit pilot-based transmissions.

[0224] The gNB may transmit, to the UE included in Si, a scheduling grant (e.g., UL grant on physical uplink shared channel). The gNB may transmit, to the UE included in Si, the scheduling grant via DCI.

[0225] The gNB may transmit, to the UE included in Si, second configuration information. The gNB may transmit, to the UE included in Si, the second configuration information 20 via RRC, DCI or MAC CE.

[0226] If the gNB determines that a UE included in S2 is in the cell provided by the gNB and the UE included in S2 uses the mask of REs for pilot-based transmissions, the gNB may transmit, to the UE included in Si, second configuration information indicating that some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions are to be muted in a mask of REs for transmissions.

[0227] The second configuration information may indicate some or all REs mapped to pilot symbols within the mask of REs for pilot-based transmissions are to be muted, to be 30 mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols, in a mask of REs for transmissions.

[0228] In an example, the second configuration information may indicate a mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols. The second configuration information may indicate an index of a mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols. The second configuration information may indicate a configuration parameter to build the mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols.

[0229] The REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols within the mask of REs for transmissions may correspond to some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions. The mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols may be indicated with at least one of an index of a RE to be muted, a density in time of REs to be muted or a density in frequency of REs to be muted.

[0230] The second configuration information may indicate a number or index(es) of code division multiplexing (CDM) group(s) without data that should be muted based on the mask of REs for pilot-based transmissions.

[0231] If the gNB determines that a UE included in S2 is not in the cell provided by the gNB or the UE included in 52 does not use the mask of REs for pilot-based transmissions, the gNB may transmit, to the UE included in Si, second configuration information indicating that some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols in a mask of REs for transmissions.

[0232] The UE included in Si may determine a mask of REs for transmissions based on the first configuration information and the second configuration information. The mask of REs for transmissions may be a mask of REs for pilotless transmissions or a mask of REs for hybrid pilotless transmissions and pilot-based transmissions.

[0233] The UE included in Si may transmit, to the gNB transmissions based on the mask of REs for pilotless transmissions.

[0234] Subsequently, the gNB may re-determine whether a UE included in S2 is in the cell provided by the gNB. The gNB may re-determine whether the UE included in 52 uses the mask of REs for pilot-base transmissions to transmit pilot-based transmissions.

[0235] The gNB may transmit, to the UE included in Si, a scheduling grant (e.g., UL grant on physical uplink shared channel). The gNB may transmit, to the UE included in Si, the scheduling grant via DCI.

[0236] The gNB may transmit, to the UE included in Si, third configuration information. The gNB may transmit, to the UE included in Si, the third configuration information via DCI or MAC CE.

[0237] If the gNB determines that a UE included in S2 is in the cell provided by the gNB and the UE included in S2 uses the mask of REs for pilot-based transmissions, the gNB may transmit, to the UE included in Si, third configuration information indicating that some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions are to be muted in a mask of REs for transmissions.

[0238] The third configuration information may indicate some or all REs mapped to pilot symbols within the mask of REs for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols, in a mask of REs for transmissions.

[0239] In an example, the third configuration information may indicate a mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols. The third configuration information may indicate an index of a mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols. The third configuration information may indicate a configuration parameter to build the mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols.

[0240] The REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols within the mask of REs for transmissions may correspond to some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions. The mask for transmissions indicating REs to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols may be indicated with at least one of an index of a RE to be muted, a density in time of REs to be muted or a density in frequency of REs to be muted.

[0241] The third configuration information may indicate a number or index(es) of code division multiplexing (CDM) group(s) without data that should be muted based on the mask of REs for pilot-based transmissions.

[0242] If the gNB determines that a UE included in S2 is not in the cell provided by the gNB or the UE included in S2 does not use the mask of REs for pilot-based transmissions, the gNB may transmit, to the UE included in Si, third configuration information indicating that some or all REs mapped to pilot symbols or to be muted within the mask of REs for pilot-based transmissions are to be mapped to data symbols or to be mapped to data symbols acting as pilot symbols in a mask of REs for transmissions.

[0243] The UE included in Si may re-determine a mask of REs for transmissions based on the first configuration information, the second configuration information and the third configuration information. The mask of REs for transmissions may be a mask of REs for pilotless transmissions or a mask of REs for hybrid pilotless transmissions and pilot-based transmissions.

[0244] The UE included in Si may transmit, to the gNB transmissions based on the mask of REs for pilotless transmissions.

[0245] Fig. 8 shows a schematic representation of a transmission chain of a UE in Si.

[0246] The UE in Si may receive data bits. The UE in Si may extract a required number of data bits for a slot. The UE in Si may divide the number of data bits into first vectors of data bits and second vectors of data bits.

[0247] The UE in Si may calculate a cyclic redundancy (CRC) check for each first vector of data bits and may include the CRC in each first vector of data bits.

[0248] The UE in Si may calculate a CRC check for each second vector of data bits and may include the CRC in each second vector of data bits.

[0249] The UE in Si may select a first MCS index in a regular MCS table. The UE in Si may select a second MCS index in a robust MCS table. The regular MCS table may comprise MCSs with same modulation orders than MCSs in the robust MCS table.

[0250] The robust MCS table may comprise MCSs with lower coding rates than MCSs in the regular MCS table. Alternatively, the regular MCS table may comprise MCSs with same coding rates than MCSs in the robust MCS table. The robust MCS table may comprise MCSs with lower modulation orders than MCSs in the regular MCS table.

[0251] Data symbols may be generated using the MCS associated with the first MCS index. Data symbols acting as virtual pilot symbols may be generated using the MCS associated with the second MCS index. In this way, data symbols acting as virtual pilot symbols are more likely to be successfully demodulated and decoded in poor radio conditions (e.g., low signal to noise (SNR) ratio) than data symbols.

[0252] It will be understood that the lower the coding rate, the more robust the MCS. and the more likely the In an implementation, the UE in Si may encode, map and modulate.

[0253] The UE in Si may encode first vectors of data bits into first encoded vectors of data bits using the MCS associated with the first MCS index. The UE in Si may map the first encoded vectors of data bits to REs mapped to data symbols within a mask of REs for pilotless transmissions. The UE in Si may modulate the first encoded vectors of data bits into data symbols using the MCS associated with the first MCS index.

[0254] The UE in Si may encode second vectors of data bits into second encoded vectors of data bits using the MCS associated with the second MCS index. The UE in Si may map the second encoded vectors of data bits to REs mapped to data symbols acting as virtual pilot symbols within a mask of REs for pilotless transmissions. The UE in Si may modulate the second encoded vectors of data bits into data symbols acting as virtual pilot symbols using the MCS associated with the second MCS index.

[0255] In another implementation, the UE in Si may encode, modulate and map.

[0256] The UE in Si may encode first vectors of data bits into first encoded vectors of data 20 bits using the MCS associated with the first MCS index. The UE in Si may modulate the first encoded vectors of data bits into data symbols using the MCS associated with the first MCS index.

[0257] The UE in Si may encode second vectors of data bits into second encoded vectors of 25 data bits using the MCS associated with the second MCS index. The UE in Si may modulate the second encoded vectors of data bits into data symbols acting as pilot symbols using the MCS associated with the second MCS index.

[0258] The UE in Si may map the data symbols to REs mapped to data symbols within a 30 mask of REs for pilotless transmissions. The UE in Si may map the data symbols acting as virtual pilot symbols to REs mapped to data symbols acting as virtual pilot symbols within a mask of REs for pilotless transmissions.

[0259] The REs mapped to data symbols acting as virtual pilot symbols within a mask of REs for pilotless transmissions may be with a same (e.g., may form a whole) OFDM symbol or may be within a same (e.g., may form a whole) slot.

[0260] The UE in Si may transmit the pilotless transmissions.

[0261] The gNB may receive the pilotless transmissions.

[0262] The gNB may extract the data symbols and the data symbols acting as virtual pilot symbols based on the mask of REs for pilotless transmissions.

[0263] The gNB may attempt to demodulate the data symbols into first encoded vectors of data bits based on the first index of MCS. The gNB may attempt to decode the first encoded vectors of data bits into first vectors of data bits based on the first index of MCS.

[0264] Each vector of data bits may include a CRC. The gNB may calculate a CRC and may determine if the calculated CRC matches the CRC included in the first vector of data bits. If the calculated CRC matches the CRC included in the first vector of data bits, the data symbol is successfully demodulated and decoded. If the calculated CRC does not match the CRC included in the first vector of data bits, the data symbol is unsuccessfully demodulated and decoded.

[0265] The gNB may attempt to demodulate the data symbols acting as virtual pilot symbols into second encoded vectors of data bits based on the second index of MCS. The gNB may attempt to decode the second encoded vectors of data bits into second vectors of data bits based on the second index of MCS.

[0266] Each second vector of data bits may include a CRC. The gNB may calculate a CRC and may determine if the calculated CRC matches the CRC included in the second vector of data bits. If the calculated CRC matches the CRC included in the second vector of data bits, the data symbol acting as virtual pilot symbol is successfully demodulated and decoded. If the calculated CRC does not match the CRC included in the second vector of data bits, the data symbol acting as pilot symbol is unsuccessfully demodulated and decoded.

[0267] Fig. 9 shows a schematic representation of a reception chain of a gNB. The reception chain of the gNB implements an iterative algorithm.

[0268] The gNB may receive the pilotless transmissions.

[0269] The gNB may extract the data symbols and the data symbols acting as virtual pilot symbols based on the mask of REs for pilotless transmissions.

[0270] The gNB may attempt to demodulate the data symbols into first encoded vectors of 15 data bits based on the first index of MCS. The gNB may attempt to decode the first encoded vectors of data bits into first vectors of data bits based on the first index of MCS.

[0271] Each vector of data bits may include a CRC. The gNB may calculate a CRC and may determine if the calculated CRC matches the CRC included in the first vector of data bits. If the calculated CRC matches the CRC included in the first vector of data bits, the data symbol is successfully demodulated and decoded. If the calculated CRC does not match the CRC included in the first vector of data bits, the data symbol is unsuccessfully demodulated and decoded.

[0272] The gNB may attempt to demodulate the data symbols acting as virtual pilot symbols into second encoded vectors of data bits based on the second index of MCS. The gNB may attempt to decode the second encoded vectors of data bits into second vectors of data bits based on the second index of MCS.

[0273] Each second vector of data bits may include a CRC. The gNB may calculate a CRC and may determine if the calculated CRC matches the CRC included in the second vector of data bits. If the calculated CRC matches the CRC included in the second vector of data bits, the data symbol acting as virtual pilot symbol is successfully demodulated and decoded. If the calculated CRC does not match the CRC included in the second vector of data bits, the data symbol acting as pilot symbol is unsuccessfully demodulated and decoded.

[0274] In a scenario, if the data symbols acting as pilot symbols are unsuccessfully demodulated and decoded, the gNB may transmit, to the UE in Si, request to retransmit the pilotless transmissions.

[0275] In another scenario, if the data symbols and the data symbols acting as pilot symbols are successfully demodulated and decoded, the first vectors of data bits and the second vectors of data bits are combined in a single vector of data bits.

[0276] In another scenario, if the data symbols are not successfully demodulated and decoded and the data symbols acting as pilot symbols are successfully demodulated and decoded, a counter value may be updated (e.g., increased or decreased).

[0277] If the counter value has not reached a threshold, the gNB may re-attempt to demodulate and decode the data symbols into first vectors of data bits based on the first index of MCS and the data symbols acting as virtual pilot symbols. For example, the data symbols acting as virtual pilot symbols may be used to perform channel estimation and the channel estimation may be used to equalize the data symbols.

[0278] If the counter value has reached the threshold, the gNB may not re-attempt to demodulate the data symbols into first encoded vectors of data bits based on the first index of MCS. The gNB may not attempt to decode the first encoded vectors of data bits into first vectors of data bits based on the first index of MCS. The gNB may transmit, to the UE in Si, request to re-transmit the pilotless transmission.

[0279] Fig. 10 shows a schematic representation of examples of a resource grid for pilotless transmissions in a communication system.

[0280] In an implementation, the resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols and REs mapped to data symbols. The REs mapped to data symbols acting as virtual pilot symbols may comprise the REs of a first and a second OFDM symbols. The REs mapped to data symbols may comprise the REs of third to a fourteenth OFDM symbols.

[0281] In another implementation, the resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols and REs mapped to data symbols. The REs mapped to data symbols acting as virtual pilot symbols may comprise the REs of a second and a eighth OFDM symbols. The REs mapped to data symbols may comprise the REs of a first, a third to a seventh and a ninth to a fourteenth OFDM symbols.

[0282] In another implementation, the resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols and REs mapped to data symbols. The REs mapped to data symbols acting as virtual pilot symbols may comprise every other REs of a second, a eighth and a thirteenth OFDM symbols (e.g., even frequency indexes). The REs mapped to data symbols may comprise remaining REs of the second, the eighth and the thirteenth OFDM symbols (e.g., odd frequency indexes) and REs of a first, a third to a seventh and a ninth to a twelve and a fourteenth OFDM symbols.

[0283] Fig. 11 shows a schematic representation of an example of a modulation block and a mapping block of a transmission chain of a user equipment and an example of a resource grid for pilotless transmissions in a communication system.

[0284] A UE in Si may receive, from a gNB, configuration information indicating a specific data symbol value. The configuration information may indicate a mask for pilotless transmissions indicating specific (e.g., known/ predefined) REs to be mapped to data symbols having the specific (e.g., known/predefined) data symbol value. The configuration information may indicate an index of a mask for pilotless transmissions indicating REs to be mapped to data symbols having the specific data symbol value.

[0285] In this way, data symbols acting as virtual pilot symbols may be the data symbols having the specific data symbol value as oppose to random data symbols.

[0286] The UE in Si may receive data bits. The UE in Si may extract a required number of data bits for a slot. The UE in Si may divide the number of data bits into vectors of data bits.

[0287] The UE in Si may select a MCS index in a MCS table. The UE in Si may encode vectors of data bits into encoded vectors of data bits using the MCS associated with 10 the MCS index.

[0288] The UE in Si may modulate the encoded vectors of data bits into data symbols using the MCS associated with the MCS index. The data symbols having the specific data symbol value may act as virtual pilot symbols.

[0289] The UE in Si may shuffle (e.g., arrange) the data symbols so that data symbols having the specific data symbol value may be mapped to specific REs and may act as virtual pilot symbolss. The UE in Si may shuffle (e.g., arrange) the data symbols so that other data symbols may be mapped to other REs.

[0290] It will be understood that since a shuffling operation is introduced before mapping at the UE in Si, a corresponding deshuffling operation may be introduced after demapping at the gNB.

[0291] The shuffling and mapping operations may be performed algorithmically. The shuffling and mapping operations may be based on a first Al/ML model. The first Al/ML model may be trained to output a resource grid with data symbols having the specific data symbol value mapped to the specific REs and other data symbols mapped to other REs as a response to data symbols being input.

[0292] The demapping and deshuffling operations may be performed algorithmically. The demapping and deshuffling operations may be based on a second Al/ML model. The second Al/ML model may be trained to output data symbols as a response to a resource grid with data symbols having the specific data symbol value mapped to the specific REs and other data symbols mapped to other REs being input.

[0293] Fig. 12 shows a schematic representation of a transmission chain of a UE in Si and a reception chain of a gNB.

[0294] The UE in Si may receive data bits. The UE in Si may extract a required number of data bits for a slot. The UE in Si may divide into vectors of data bits.

[0295] The UE in Si may encode vectors of data bits into encoded vectors of data bits. The UE in Si may modulate the encoded vectors of data bits into data symbols.

[0296] The UE in Si may shuffle (e.g., arrange) the data symbols so that data symbols having the specific data symbol value may be mapped to specific REs of a resource grid and may act as virtual pilot symbols based on configuration information based on a mask of REs for pilotless transmissions. The UE in Si may shuffle (e.g., arrange) the data symbols so that other data symbols may be mapped to other REs of the resource grid based on configuration information based on the mask of REs for pilotless transmissions.

[0297] The UE in Si may apply OFDM modulation to the resource grid. OFDM modulation may include IDFT transformation.

[0298] The UE in Si may transmit pilotless transmissions.

[0299] The gNB may receive the pilotless transmissions.

[0300] The gNB may apply to OFDM demodulation to obtain a resource grid. OFDM 30 demodulation may include DFT transformation.

[0301] The gNB may extract the data symbols and the data symbols acting as virtual pilot symbols based on the mask of REs for pilotless transmissions.

[0302] The gNB may determine a channel based on the data symbols acting as virtual pilot symbols.

[0303] The gNB may equalize the data symbols and the data symbols acting as virtual pilot symbols based on the channel estimation.

[0304] The gNB may demap and deshuffle (e.g., rearrange) the data symbols and the data symbols acting as virtual pilot symbols The gNB may demodulate the data symbols and data symbols acting as virtual pilot symbols into encoded vectors of data bits. The gNB may decode the first encoded vectors of data bits into first vectors of data bits.

[0305] Fig. 13 shows a schematic representation of examples of resource grids for pilotless transmissions and examples of resource grids for pilot-based transmissions in a communication system A UE1 in Si may perform pilotless transmissions. A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols, REs mapped to data symbols and REs to be muted.

[0306] A UE2 in S2 may perform pilot-based transmissions. A resource grid may comprise REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0307] A UE3 in Si may perform pilotless transmissions. A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols, REs mapped to data symbols 30 and REs to be muted.

[0308] A UE4 in S2 may perform pilotless transmissions. A resource grid may comprise REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0309] REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the 5 UE1 in Si may correspond to REs to be muted in the resource grid of the UE2 in S2, REs to be muted in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0310] REs mapped to pilot symbols in the resource grid of the UE2 in S2 may correspond to 10 REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0311] REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the UE3 in Si may correspond to REs to be muted in the resource grid of the UE1 in Si, 15 REs to be muted in the resource grid of the UE2 in S2 and REs to be muted in the resource grid of the UE4 in 52.

[0312] REs mapped to pilot symbols in the resource grid of the UE4 in S2 may correspond to REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource 20 grid of the UE2 in S2 and REs to be muted in the resource grid of the UE3 in Si.

[0313] Estimation of the channel for a UE in Si may rely on keeping REs mapped to data symbols acting as virtual pilot symbols interference free. However, by increasing the number of UEs in Si and/or modulation order, the amount of REs mapped to data symbols acting as virtual pilot symbols may not be sufficient to achieve accurate channel estimation (due to limited observations).

[0314] To address this problem, we propose to introduce hybrid pilotless transmissions and pilot-based transmissions.

[0315] Fig. 14 shows a schematic representation of examples of resource grids for hybrid pilotless and pilot-based transmissions and examples of resource grids for pilot-based transmissions in a communication system.

[0316] A UE1 in Si may perform hybrid pilotless transmissions and pilot-based transmissions.

[0317] A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols, REs mapped to pilots, REs mapped to data symbols and REs to be muted.

[0318] A UE2 in S2 may perform pilot-based transmissions. A resource grid may comprise 10 REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0319] A UE3 in Si may perform hybrid pilotless transmissions and pilot-based transmissions. A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols, REs mapped to pilots, REs mapped to data symbols and REs to be muted.

[0320] A UE4 in S2 may perform pilotless transmissions. A resource grid may comprise REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0321] REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the 20 UE1 in Si may correspond to REs to be muted in the resource grid of the UE2 in S2, REs to be muted in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0322] REs mapped to pilot symbols in the resource grid of the UE1 in Si may correspond to 25 REs to be muted in the resource grid of the UE2 in S2, REs to be muted in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0323] REs mapped to pilot symbols in the resource grid of the UE2 in S2 may correspond to REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource 30 grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0324] REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the UE3 in Si may correspond to REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE2 in S2 and REs to be muted in the resource grid of the UE4 in S2.

[0325] REs mapped to pilot symbols in the resource grid of the UE3 in Si may correspond to REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE2 in S2 and REs to be muted in the resource grid of the UE4 in S2.

[0326] REs mapped to pilot symbols in the resource grid of the UE4 in S2 may correspond to REs to be muted in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE2 in S2 and REs to be muted in the resource grid of the UE3 in Si.

[0327] Another possibility is to limit or completely remove the amount of muted REs in the resource grid of UE1 in Si and UE3 in Si. This option helps to increase the spectral efficiency gain of UE1 in Si and UE3 in Si compared to UE2 in S2 and UE4 in S2. However, due to lack of interference free reception at gNB, gNB will face more difficulties in channel estimation and data symbol demodulation.

[0328] Fig. '15 shows a schematic representation of examples of resource grids for pilotless transmissions and examples of resource grids for pilot-based transmissions in a communication system.

[0329] A UE1 in Si may perform pilotless transmissions. A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols and REs mapped to data 25 symbols. The resource grid may not comprise REs to be muted.

[0330] A UE2 in S2 may perform pilot-based transmissions. A resource grid may comprise REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0331] A UE3 in Si may perform pilotless transmissions. A resource grid may comprise REs mapped to data symbols acting as virtual pilot symbols and REs mapped to data symbols. The resource grid may not comprise REs to be muted.

[0332] A UE4 in S2 may perform pilotless transmissions. A resource grid may comprise REs mapped to pilot symbols, REs mapped to data symbols and REs to be muted.

[0333] REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the UE1 in Si may correspond to REs to be muted in the resource grid of the UE2 in 52, REs mapped to data in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2.

[0334] REs mapped to pilot symbols in the resource grid of the UE2 in 52 may correspond to REs mapped to data in the resource grid of the UE1 in Si, REs mapped to data in the resource grid of the UE3 in Si and REs to be muted in the resource grid of the UE4 in S2 REs mapped to data symbols acting as virtual pilot symbols in the resource grid of the UE3 in Si may correspond to REs mapped to data in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE2 in S2 and REs to be muted in the resource grid of the UE4 in S2.

[0335] REs mapped to pilot symbols in the resource grid of the UE4 in S2 may correspond to REs mapped to data in the resource grid of the UE1 in Si, REs to be muted in the resource grid of the UE2 in S2 and REs mapped to data in the resource grid of the UE3 in Si.

[0336] Fig. 16 shows a block diagram of an example of method for managing pilotless transmissions or pilot-based transmissions in a communication system. The method may be performed by an apparatus (e.g., UE).

[0337] At step 1600, the apparatus may transmit, to a BS, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions.

[0338] At step 1602, the apparatus may receive, from the BS, configuration information based on the capability information.

[0339] At step 1604, the apparatus may transmit, to the BS, pilotless transmissions or pilot-s based transmissions based on the configuration information.

[0340] Fig. 17 shows a block diagram of an example of method for managing pilotless transmissions or pilot-based transmissions in a communication system. The method may be performed by an apparatus (e.g., BS).

[0341] At step 1700, the apparatus may receive, from a UE, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions.

[0342] is At step 1702, the apparatus may transmit, to the UE, configuration information based on the capability information.

[0343] At step 1704, the apparatus may receive, from the UE, pilotless transmissions or pilot-based transmissions based on the configuration information.

[0344] At step 1706, the apparatus may determine a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

[0345] Fig. 18 shows a block diagram of an example of method for managing pilotless 25 transmissions in a communication system. The method may be performed by an apparatus (e.g., UE).

[0346] At step 1800, the apparatus may transmit, to a BS, capability information indicating a capability to support pilotless transmissions.

[0347] At step 1802, the apparatus may receive, from the BS, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions.

[0348] At step 1804, the apparatus may receive, from the BS, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions.

[0349] At step 1806, the apparatus may transmit, to the BS, transmissions based on the first configuration information and the second configuration.

[0350] Fig. 19 shows a block diagram of an example of method for managing pilotless 15 transmissions in a communication system. The method may be performed by an apparatus (e.g., BS).

[0351] At step 1900, the apparatus may receive, from a UE, capability information indicating a capability to support pilotless transmissions.

[0352] At step 1902, the apparatus may transmit, to the UE, first configuration information indicating a mask of resource elements for pilot-based transmissions or an index to a mask of resource elements for pilot-based transmissions.

[0353] At step 1904, the apparatus may transmit, to the UE, second configuration information indicating whether some or all resource elements mapped to pilot symbols or to be muted within the mask of resource elements for pilot-based transmissions are to be muted, to be mapped to data symbols or to be mapped to data symbols acting as virtual pilot symbols in a mask of resource elements for transmissions.

[0354] At step 1906, the apparatus may receive, from the UE, transmissions based on the first configuration information and the second configuration.

[0355] Fig. 20 shows a schematic representation of non-volatile memory media 1000 storing instructions which when executed by a processor allow the processor to perform one or more of the steps of the methods of Fig. 16 to Fig. 19.

[0356] It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0357] It will be understood that although the above concepts have been discussed in the context of 5G and 6G, one or more of these concepts may be applied to other generations of cellular systems.

[0358] The embodiments may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0359] The embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures, e.g., as in Fig. 16 to Fig. 19, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

[0360] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi-core processor architecture, as non-limiting examples.

[0361] Alternatively or additionally some embodiments may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device.

[0362] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0363] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example integrated device.

[0364] The term "means" as used in the description and in the claims may refer to one or more individual elements configured to perform the corresponding recited functionality or functionalities, or it may refer to several elements that perform such functionality or functionalities. Furthermore, several functionalities recited in the claims may be performed by the same individual means or the same combination of means. For example, performing such functionality or functionalities may be caused in an apparatus by a processor that executes instructions stored in a memory of the apparatus.

[0365] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

1. CLAIMS1. An apparatus comprising: means for transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; means for receiving, from the base station, configuration information based on the capability information; and means for transmitting, to the base station, pilotless transmissions or pilot-transmissions based on the configuration information.

2. The apparatus of claim 1, wherein the capability information indicates a capability to support pilotless transmissions.

3. The apparatus of claim 2, comprising: means for transmitting, to the base station, configuration information indicating at least one of: a mask of resource elements for pilotless transmissions; an index of a mask of resource elements for pilotless transmissions; or a configuration parameter to reconstruct a mask of resource elements for pilotless transmissions.

4. The apparatus of claim 2 or claim 3, wherein the configuration information indicates at least one of: a request to perform pilotless transmissions; a mask of resource elements for pilotless transmissions; an index of mask of resource elements for pilotless transmissions; a request to use a first transmission power for transmitting data symbols acting as virtual pilot symbols different from a second transmission power for transmitting data symbols; a request to use a first code rate for generating data symbols acting as virtual pilot symbols different from a second code rate for generating data symbols; or a request to use a first modulation order for generating data symbols acting as virtual pilot symbols different from a second modulation order for generating data symbols.

5. The apparatus of claim 3 or claim 4, wherein the mask of resource elements for pilotless transmissions indicates at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to data symbols acting as virtual pilot symbols.

6. The apparatus of claim 5, wherein the mask of resource elements for pilotless transmissions does not indicate resource elements muted.

7. The apparatus of any of claims 4 to 6, wherein the means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information comprises: means for generating data symbols acting as virtual pilot symbols using the first code rate or first modulation order; means for generating data symbols using the second code rate or second modulation order; and means for transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

8. The apparatus of any of claims 4 to 7, wherein the means for transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information comprises: means for setting a transmission power for data symbols acting as virtual pilot symbols based on the first transmission power; means for setting a transmission power for data symbols based on the second 30 transmission power; and means for transmitting, to the base station, the data symbols acting as virtual pilot symbols and the data symbols.

9. The apparatus of any of claims 2 to 8, wherein means for receiving, from the base station, configuration information based on the capability information comprises: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicates at least one of: a specific data symbol value; a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value; or an index of a mask for pilotless transmissions indicating resource elements to be mapped to data symbols having the specific data symbol value.

10. The apparatus of claim 1, wherein the capability information indicates a capability to support pilot-based transmissions. 15

11. The apparatus of claim 10, wherein means for receiving, from the base station, configuration information based on the capability information comprises: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one Of: a request to perform pilot-based transmissions a mask of resource elements for pilot-based transmissions; an index of a mask of resource elements for pilot-based transmissions; or a request to use a first transmission power for transmitting pilot symbols different from a second transmission power for transmitting data symbols.

12. The apparatus of claim 11, wherein the mask of resource elements for pilot-based transmissions indicates at least one of: resource elements muted; resource elements mapped to data symbols; or resource elements mapped to pilot symbols.

13. The apparatus of claim 1, wherein the capability information indicates a capability to support pilotless transmissions.

14. The apparatus of claim 13, wherein means for receiving, from the base station, configuration information based on the capability information comprises: means for receiving, from the base station, configuration information based on the capability information, wherein the configuration information indicate at least one of: a request to perform hybrid pilotless transmissions and pilot-based 10 transmissions; a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions; or an index of a mask of resource elements for a hybrid pilotless transmissions and pilot-based transmissions.

15. The apparatus of claim 14, wherein the mask of resource elements for hybrid pilotless transmissions and pilot-based transmissions indicates at least one of: resource elements muted; resource elements mapped to data symbols; resource elements mapped to data symbols acting as virtual pilot symbols; or resource elements mapped to pilot symbols.

16. The apparatus of any of claims 1 to 15, wherein the configuration information is received via radio resource control, downlink control information or medium access control control element.

17. An apparatus comprising: means for receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; means for transmitting, to the user equipment, configuration information based on the capability information; means for receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and means for determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.

18. The apparatus of claim 17, wherein the means for receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information comprises: means for receiving, from the user equipment, pilotless transmissions based on the configuration information; and wherein the means for determining a channel response based on the pilotless transmissions or pilot-based transmissions comprises: means for demodulating and decoding data symbols acting as virtual pilot symbols based on the configuration information; and means for determining the channel response based on the demodulated and decoded data symbols acting as virtual pilot symbols.

19. The apparatus of claim 18, wherein the means for receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information comprises: means for receiving, from the user equipment, pilot-based transmissions based on the configuration information; and wherein the means for determining a channel response based on the pilotless transmissions or pilot-based transmissions comprises: means for extracting pilot symbols based on the configuration information; and means for determining the channel response based on the extracted pilot symbols.

20. The apparatus of claim 18 or claim 19, wherein the means for determining the channel response based on the extracted data symbols acting as virtual pilot symbols comprises: means for providing the extracted data symbols acting as virtual pilot symbols to a channel estimator as an input to obtain the channel response as an output; or wherein the means for determining the channel response based on the extracted pilot symbols comprises: means for providing the extracted pilot symbols to a channel estimator as an input to obtain the channel response as an output.

21. A method comprising: transmitting, to a base station, capability information indicating a capability to support pilotless transmissions or a capability to support pilot-based transmissions; receiving, from the base station, configuration information based on the capability information; and transmitting, to the base station, pilotless transmissions or pilot-based transmissions based on the configuration information

22. A method comprising: receiving, from a user equipment, capability information, wherein the capability information indicates at least one of a capability to support pilotless transmissions or a capability to support pilot-based transmissions; transmitting, to the user equipment, configuration information based on the capability information; receiving, from the user equipment, pilotless transmissions or pilot-based transmissions based on the configuration information; and determining a channel response based on the pilotless transmissions or pilot-based transmissions and the configuration information.