GB2640639A - UE antenna port configuration for 2 layer UL MIMO - Google Patents

Abstract

This application concerns UEs which have a dynamic antenna port configuration (DAPC) capability. A UE sends a capability report 304 to network equipment (e.g. a gNB) which includes an indication of whether the UE support DAPC. The UE preferably informs 308 the network equipment of the current antenna port configuration (DAPC) and transmits sounding reference signals (SRS) 310 to the network node. The network node determines 312 the best uplink (UL) precoding values or transmission precoding matrix indicator (TPMI), based on at least the DAPC capability of the UE, but advantageously on its current DAPC. The network node configures 314 the UE with such pre-coding values for UL-MIMO transmission.

Description

UE ANTENNA PORT CONFIGURATION FOR 2 LAYER UL MIMO TECHNICAL FIELD [0001] The example and non-limiting embodiments relate generally to antenna ports and, more particularly, to a dynamic antenna port configuration.

BRIEF DESCRIPTION OF PRIOR DEVELOPMENTS

[0002] Use of logical uplink antenna ports and logical downlink antenna ports, for communication between a user equipment and a network equipment, is known.

SUMMARY OF THE INVENTION

[0003] The following summary is merely intended to be an example. The summary is not intended to limit the scope of the claims.

[0004] In accordance with one aspect, an example apparatus is provided comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: send capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and receive, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0005] In accordance with another aspect, an example method is provided comprising: sending capability information to a network equipment regarding a capability of an apparatus to support a dynamic antenna port configuration; and receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0006] In accordance with another aspect, an example apparatus is provided comprising: means for sending capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and mean for receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0007] In accordance with another aspect, an example embodiment is provided with a program storage device readable by an apparatus, tangibly embodying a program of instructions executable with the apparatus for performing operations, the operations comprising: sending capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0008] In accordance with another aspect, an example apparatus is provided comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: receive, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determine, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0009] In accordance with another aspect, an example method is provided comprising: receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0010] In accordance with another aspect, an example apparatus is provided comprising: means for receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and means for determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0011] In accordance with another aspect, an example embodiment is provided with a program storage device readable by an apparatus, tangibly embodying a program of instructions executable with the apparatus for performing operations, the operations comprising: receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0012] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are provided in subject matter of the dependent claims.

BRIEF DESCRIPTION OF DRAWINGS

[0013] The foregoing aspects and other features are explained in the following description, taken in connection with the accompanying drawings, wherein: [0014] FIG. 1 is a block diagram of one possible and non-limiting example system in which the example embodiments may be practiced; [0015] FIG. 2A is a diagram illustrating an example embodiment at a user equipment; [0016] FIG. 2b is a diagram illustrating an example embodiment at a user equipment; [0017] FIG. 3 is a diagram illustrating an example method; [0018] FIG. 4 is a diagram illustrating an example method; [0019] FIG. 5 is a diagram illustrating an example method.

DETAILED DESCRIPTION

[0020] The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows: 3 GPP third generation partnership project 5G fifth generation 5GC 5G core network 6G sixth generation AN/IF access and mobility management function ANT antenna AP antenna port CA carrier aggregation CE control element CSI channel state information CU central unit DAPC dynamic antenna port configuration DC dual connectivity DCI downlink control information DFT discrete Fourier transform DL downlink MARS demodulation reference signals DU distributed unit eNB (or eNodeB) evolved Node B (e.g., an LTE base station) EN-DC E-UTRA-NR dual connectivity en-gNB or En-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DC E-UTRA evolved universal terrestrial radio access, i e, the LTE radio access technology FS free space gNB (or gNodeB) base station for 5G/NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC H-Matrix hierarchical matrix I/F interface LLS link level simulation LTE long term evolution MAC medium access control MiMo or MIMO multiple input multiple output MME mobility management entity Msg I message I ng or NG new generation ng-eNB or NG-eNB new generation eNB NR new radio N/W or NW network PA power amplifier PDCP packet data convergence protocol PHY physical layer PUCCH physical uplink control channel PUSCH physical uplink shared channel RACH random access channel RAN radio access network Rel release RF radio frequency RH right hand RLC radio link control RNTI radio network temporary identifier RRC radio resource control RRH remote radio head RU radio unit Rx receiver SDAP service data adaptation protocol SGW serving gateway SINR signal to noise ratio SLS system level simulation SMF session management function SRS sounding reference signal TMPI transmitted precoding matrix indicator

TS technical specification

Tx transmitter UCI uplink control information UE user equipment (e g, a wireless, typically mobile device) UL uplink ULA unique local address UPF user plane function [0021] Turning to FIG. 1, this figure shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. Examples of network equipment, network device, or a network entity might be understood to include, at least part of, a transmission reception point or a cell or a gNB or node for example. In the example of FIG. 1, the user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE, 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers HO are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, comprising one of or both parts 140- 1 and/or 140-2, which may be implemented in a number of ways. The module 140 may be implemented in hardware as module 140-1, such as being implemented as part of the one or more processors 120. The module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[0022] The RAN node 170 in this example is a base station that provides access by wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for example, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or a ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (such as, for example, the network element(s) 190). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the Fl interface connected with the gNB-DU. The Fl interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the Fl interface 198 connected with the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of a RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195.

The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station or node.

[0023] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F(s)) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory/memories and processor(s), and/or other hardware, but these are not shown.

[0024] The RAN node 170 includes a module 150, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The module 150 may be implemented in hardware as module 150-1, such as being implemented as part of the one or more processors 152. The module 1501 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 150 may be implemented as module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[0025] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more gNBs 170 may communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, for example, an Xn interface for SG, an X2 interface for LTE, or other suitable interface for other standards.

[0026] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH/DU, and the one or more buses 157 could be implemented in part as, for example, fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node 170 to the RRH/DU 195. Reference 198 also indicates those suitable network link(s).

[0027] It is noted that description herein indicates that "cells" perform functions, but it should be clear that equipment which forms the cell will perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For example, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single base station's coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So if there are three 120 degree cells per carrier and two carriers, then the base station has a total of 6 cells.

[0028] The wireless network 100 may include a network element or elements 190 that may include core network functionality, and which provides connectivity via a link or links 181 with a further network, such as a telephone network and/or a data communications network (e.g., the Internet). Such core network functionality for 50 may include access and mobility management function(s) (AMF(S)) and/or user plane functions (UPF(s)) and/or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality These are merely exemplary functions that may be supported by the network el ement(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to a network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an S1 interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/W IlF(s)) 180, interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0029] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[0030] The computer readable memories 125, 155, and 171 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, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 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) and processors based on a multi-core processor architecture, as non-limiting examples. The processors 120, 152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, and other functions as described herein.

[0031] In general, the various embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

[0032] There are generally three different types of UL transmission schemes: not-configured, codebook based and non-codebook based. The scheme is determined by a RRC parameter txConfig. Codebook-based UL transmission in mobile communications involves a method where the UE determines its transmission strategy using a predefined set of precoding vectors, known as a codebook. A transmitted precoding matrix indicator (TPMI) sets a TPMI Index when codebook-based transmission is enabled, and the range is based on the number of layers and number of antenna ports. Codebook based UL transmission relies on an indicated SRS resource to determine the codebook, and TPMI values to indicate which precoder to use from that codebook for the transmission. The number of layers is also indicated. With a codebook based UL transmission, the contents of a DCI parameter may comprise a SRS resource indicator (SRI), precoding and number of layers (TPMI + rank).

[0033] Conventional SRS procedures are described in the following for example: * TS 38.211 -NR; Physical channels and modulation.

* TS 38.214 -NR; Physical layer procedures for data.

* TS 38.306 -NR; User Equipment (TIE) radio access capabilities.

* TS 38.621 -Telecommunication management; Configuration Management (CM); Generic network resources Integration Reference Point (1RP); Requirements For example, TS 38.211 includes Tables 6.3.1.5-(4-7) which show precoding matrixes.

[0034] Features as described herein may be used in regard to a single-layer or multi-layer UL transmission from a UE with a higher number of possible antennas that can be used for UL transmission at the same frequency than the actual number of simultaneously supported UL layers. Both a single-layer MIMO transmission and a multi-layer MIMO may be pre-coded. Thus, an uplink MIMO transmission may be a single-layer MIMO transmission or a multi-layer MIMO transmission. In addition, pre-coding can be used for transmissions on multiple antenna port at the same frequency.

[0035] Characterization of a channel between a gNB and a UE, can be performed in either the DL direction by, for example, the gNB sending specific reference signals (CSI and/or DMRS), or in the UL direction by the UE transmitting SRS signals. Channel characterization is needed in both DL and UL directions for FDD bands, while for TDD bands channel reciprocity can be assumed for both DL and UL communications. The DL channel characterization can be performed in either DL at the UE and/or UL when the gNB is assumed to have a known and calibrated reciprocal antenna manifold. However, this antenna manifold reciprocity cannot be assumed for certain devices, such as handheld devices for example, where the UL channel has to be characterized with UE transmitted SRSs, as most UEs cannot accurately predict their best UL precoding values from the CSI-RS based DL channel characterization. Known and calibrated antenna manifold enables non-codebook-based precoding. The channel characterization/estimation is including the antennas, so known or unknown antenna manifold is not important for the characterization/estimation. For codebook (CB) based uplink, the gNB does not need reciprocal calibrated antenna manifold since the codebook based UL MIMO is based on UE SRS. Thus, as noted above, when the gNB is assumed to have a known and calibrated reciprocal antenna manifold, the DL channel characterization can be performed at the UE in either downlink, or uplink, or both downlink and uplink.

[0036] A radio channel is typically characterized for the highest number of active antenna ports (AP) at the UE in either DL or UL. As such, a UE supporting 4 DL layers will characterize the channel using 4 Logical DL AP at both the gNB and the DE; resulting in a 4x4 channel characterization. The gNB or the UE will use this information to determine a number of supported layers and the best pre-coding of those layers.

[0037] A UE supporting 4 layers in DL could be configured to transmit an SRS on each of its 4 logical DL APs for a full 4x4 channel characterization; which will be valid for DL communication. However, that channel characterization cannot always directly be used for UL if that UE is supporting less layers in UL than in DL. This is because logical UL AP selection and limitations at the UE is unknown to the network. This has not been a big issue until now because most UEs only supported one UL layer at the same frequency; whereby no pre-coding was needed in UL. However, UEs supporting 2-layer UL at a same frequency are now emerging and expected to be a more common feature for higher-tier UEs compliant with 5G advance and 6G in general.

[0038] A straightforward solution to this issue of UEs having more logical APs in DL than in UL at the same frequency is to limit the additional UL channel characterization to 2x2.

Thus, the UE would only send SRS on two selected logical UL APs. However, this can result in a suboptimal multi-layer's performance because the UE will have to select two out of the four physical antennas for the channel characterization based on, for example, downlink per logical DL AP power alone. In addition, this will also increase the signaling overhead because two different SRS based channel configurations will have to the maintained for both DL (periodic) and UL (aperiodic).

[0039] Features as described herein may be used as a novel and inventive procedure where, for example, a 4x4 SRS based channel characterization can be optimally used for UL DFT based precoding for a UE having less simultaneously logical UL APs than logical DL APs.

[0040] In one example, the following is assumed for a codebook (CB) based uplink MIMO pre-coding scenario: * A UE supporting 4 layers in DL and 2 layers in UL, which is communicated to the gNB via the UE capability report (legacy reporting).

* The channel between the gNB and the UE is characterized as a 4x4 H-Matrix based on SRS reference signals (for None-Codebook-Based (NCB) DL MiMo).

The gNB could in theory also find the best pre-coding for a 2x2 UL transmission using the available 4x4 channel matrix. However, that assumes a UE with full UL RF front end switching capabilities, where each of the two supported UL layers can be switched to any of the 4 antennas used for DL.

[0041] A UE in a deployment that supports UL MIMO, and can sequentially transmit an SRS on each of its 4 logical DL APs, will have different logical UL AP switching capabilities for simultaneously MIMO transmission, as highlighted below and shown in FIGS. 2A and 2B. FIGs. 2A and 2B show different hardware implementations for a UE with two PAs transmitting at the same frequency and four antennas for each of the 4 logical DL APs. The UE could have one or more different PA, that can be configured for simultaneously transmission of different frequencies (not shown in the figures).

[0042] FIG. 2A shows two power amplifiers (PA) 202A, 202B (which are UL antenna ports) each to a set of antennas (logical DL antenna ports), where some TPM I combinations are not valid. Four UL antennas (Ant#1, Ant#2, Ant#3, Ant#4) are shown sharing the two PAs to provide a medium flexibility. In this example, the first PA can be switched between a first set of antennas (Ant#1, Ant#2) and a second PA can be switched between a second set of antennas (Ant#3, Ant#4). Some high-tier and mid/tier mobile devices could support this. In the example embodiment of FIG. 2A two switches 204A, 204B are provided.

[0043] FIG. 2B shows two power amplifiers (PA) 202A, 202B (which are UL antenna ports) each to all four logical DL antenna ports, where all TMPI combinations might be valid. The four UL antennas (Ant#1, Ant#2, Ant#3, Ant#4) are shown sharing the two PAs. Full flexibility may be provided where each of the 2 power amplifiers (PA) can be switched to any of the four antennas. Some High-tier devices could support this. In the example embodiment of FIG. 2B four switches 206A-206D are provided. The switches 206C-206D are three pole switches. FIGS. 2A and 2B are merely some examples and should not be considered as limiting. UEs can be implemented with other logical UL AP switching capabilities than those shown in FIGS. 2A-2B, and features as described herein are valid for all possible UE switching implementations. In addition, the invalid TPMI logical UL AP combination shown in FIG. 2B might as well be logical DL AP1/AP3 and logical DL AP2/AP4, or logical DL AP1/AP4 and logical DL AP2/AP3; depending on the dynamical AP to physical antenna allocation at the UE. There may be a TPMI limitation due to UE hardware. This is not shown in Fig 2B, but as seen in Fig. 2A, the invalid TPMI combinations would be AP1/AP2 and AP3/AP3. There may also be a TPIVII limitation due to a AP being used for another connections such as, for example, CA, EN-DC, etc. [0044] A dynamic antenna port configuration (DAPC) as described herein may be a static UE capability when looking at pre-coding UL transmission alone. However, a UE supporting multi-layer UL transmission at the same frequency, can also support additional UL transmissions at other frequencies such as, for example, UL carrier aggregation (CA) and/or dual connectivity (EN-DC). This may dynamically affect the available logical DL APs for a multi-layer UL transmission at the same frequency. UL transmissions from different Tx chains in a RF transceiver are performed from different antennas to avoid unwanted (noncompliant) spurious emission.

[0045] With features as described herein, a UE supporting UL MIMO transmission, at the same frequency and at the same time, also can transmit on different frequencies (such as with UL-CA or EN-DC for example) and, for optimal UL pre-coding determination at the gNB, can be configured to dynamically communicate to the gNB the UE's current logical DL-to-UL antenna port configuration for UL MIMO -transmission at the same frequency.

This may be for when the available channel characterization is performed with a higher number of logical DL antenna ports than supported by the multi-layer UL transmission (logical UL APs). The dynamic antenna port configuration (DAPC) method as described herein may also inform the gNB of possible invalid TMPI indexes [0046] The dynamic antenna port configuration method may include the following steps: * The UE is RRC connected to the gNB and, as part of a UE capability Report, the UE may inform the gNB that the UE has support for a DAPC command.

* The gNB may configure the UE to transmit one SRS per supported logical DL AP. The LE may inform the gNB of the LTE's current UL AP configuration (DAPC), such as Codebook Based Uplink MIMO pre-coding for example (which may also be referred to as "CB-UL MIMO" with an initial definition). Pre-coding is used for MiMo where a device is transmitting one or more layers on two or more antennas.

* The UE may transmit SRSs, and the gNB may determine the optimal UL pre-coding for the UE based on the full channel characterization and the received DAPC. The derived precoding value or a TPMI index may be communicated back to the UE such as via a DCI for example.

[0047] Referring also to FIG. 3, a signaling diagram regarding an example procedure for a UE to inform a gNB on its current UL AP configuration limitations, such as illustrated with FIGS. 2A and 2B or when configuration for CA or EN-DC, is shown for a dynamic logical UL AP configuration at the UE.

[0048] As illustrated with 302 the UE may utilize a RACH procedure to RRC connect to the gNB. As illustrated with 304, the UE may inform the gNB, via a capability report for example, of the UE's capability after completing the RACH procedure. This capability report may indicated to the gNB that the UE supports a DAPC command. In other words, that the UE is capable of using a dynamic antenna port configuration. For example, the UE capability report may include an indication that the UE supports dynamic AP configuration for codebook based UL MIMO pre-coding. With an example method, the capability reporting at 304 is a static one time report which the UE sends to the gNB after the RRC connection at 302. As illustrated with 306 the gNB may allocate the UE resources for SRS transmission on all configurable logical DL antenna ports. This can be sequentially, simultaneously or a combination of both.

[0049] As illustrated with 308 the LIE may inform the gNB regarding the LTE's current logical DL to logical UL antenna port relation of UL MIMO transmission. This message may be embedded to an uplink control information (UCI) command for example. As illustrated with 310 the UE may transmit an SRS per configurable logical DL antenna port.

[0050] As illustrated with 312, based on the received current logical DL to logical UL AP 30 relations from the UE, the gNB may determine a best UL pre-coding or TPMI index for the UL MIMO transmission. As illustrated with 314 the gNB may inform the UE of the chosen pre-coding values or TPMI index for the upcoming UL MIMO transmission. This could include an index for a TPMI table lookup for example. This could include precoding values or pre-coding information from the gNB for example. As illustrated with 316 the UE may transmit MIMO PUSCH using the selected pre-coding values or TPM1 index.

[0051] The following are examples of some configurations of DAPC: * Logical UL API can be configured to logical DL API or logical DL AP2, and logical UL AP2 can be configured to logical DL AP3 or logical DL AP4.

i. TMPI combinations including logical DL (API and AP2) are invalid, and TMPI combinations including logical DL (AP3 and AP4) are invalid.

ii. (IL MiMo configuration for the hardware implementation in FIG. 2A with no other active (IL schemes such as (IL-CA or EN-DC.

* Logical UL AP I can be configured to logical DL AP1, and logical UL AP 2 can be configured to logical DL AP3 or logical DL AP4.

i. Only TMPI combinations including logical DL (API and AP3) and logical DL (API and AP4) are valid.

Alo configuration for the hardware implementation in FIG. 2A where logical DL AP2 used for another UL schemes such as tIL-CA or EN-DC.

* Logical UL API can be configured to logical DL API, or logical DL AP2 or logical DL AP3, and logical UL AP2 can be configured to logical DL AP2, or logical DL AP3 or logical DL AP4.

All TMPI combinations are valid.

Maio configuration for the hardware implementation in FIG. 213 with no other active UT schemes such as UL-CA or EN-DC * Logical UL 1 can be configured to logical DL AP1 or logical DL AP3, and logical UL 2 can be configured to logical DL AP3 or logical DL AP4.

i. TMPI combinations including AP2 are invalid.

ii. UL MiA/fo configuration for the hardware implementation in FIG. 2A logical DL AP2 usedIbr another UL schemes such as UL-CA or EN-DC.

These are merely some examples and should not be considered as limiting.

[0052] Features as described herein may be used in regard to UL MIMO, TPMI, a CODEBOOK, realistic UE antenna patterns for communication devices such as smartphones for example, coverage, and non-ULA.

[0053] In one example, a 4x4 SRS based channel characterization can be optimally used for UL DFT based precoding for a UE having less simultaneously active UL APs than DL 10 APs.

[0054] DAPC may be a static UE capability when looking at pre-coding UL transmission alone. However, UE supporting UL MIMO transmission at the same frequency, can also support additional UL transmissions at other frequencies (UL Carrier Aggregation (CA) and/or EN-DC), which will dynamically affect the available AP for a UL MIMO transmission at the same frequency. A UE may be provided supporting UL MIMO transmission at the same frequency and at the same time, and can also transmit on different frequencies (UL-CA/EN-DC) with a dynamically communication regarding its current AP configuration for UL MIMO-transmission at the same frequency for optimal UL pre-coding determination at the gNB, when the available channel characterization is performed with a higher number of AP than supported by the UL MIMO transmission. The DAPC information at 308 in Fig. 3 may also inform the gNB of possible invalid TMPI indexes.

[0055] From the perspective of a user equipment (UE), a method may be provided comprising: informing, by the UE, support for a dynamic antenna port configuration (DAPC) command as part of UE capability report to a network entity; receiving configurations from the network entity (gNB) regarding transmitting by the UE a SRS per supported DL antenna port (AP); transmitting SRS signals and DAPC information via UCI to the network entity; and receiving UL pre-coding for the UE based on a full channel characterization and DL to UL antenna port (AP) relations specified by DAPC information from the network entity, wherein a derived precoding value or TPMI index is received via DCI. A 4x4 SRS based channel characterization can be optimally used for UL DFT based precoding for a UE having less simultaneously active UL APs than DL APs.

[0056] With an example embodiment and method, a UE may send information about its logical-to-physical antenna port mapping in a dynamic way. Thus, stated another way, a dynamic antenna port configuration (DAPC) is a physical-to-logical port mapping, and the port mapping may change depending upon the UE.

[0057] An example embodiment may be provided with an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: send capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and receive, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0058] The instructions, when executed with the at least one processor, may further cause the apparatus to: send information from the apparatus regarding possible invalid transmitted precoding matrix indicator indexes. The dynamic antenna port configuration may be in regard to a single-layer uplink precoding or a multi-layer uplink precoding. The single-layer or multi-layer uplink precoding may be a single-layer or a multi-layer uplink codebook based precoding. The instructions, when executed with the at least one processor, may further cause the apparatus to: send current antenna port configuration information to the network equipment. The current antenna port configuration information may comprise current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output transmission. The current antenna port configuration information may be sent with at least one of: an uplink control information command, or a physical uplink control channel, or a medium access control layer, or a medium access control layer control element. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive from the network equipment, for an upcoming uplink multiple input multiple output transmission, at least one of: an uplink precoding, or a transmitted precoding matrix indicator index. The precoding information may be configured to be used for the uplink multiple input multiple output transmission on a same frequency and, at a same time, on two of more antenna ports. The apparatus may be configured to support less layers in uplink than in downlink. The apparatus may be configured for a 4x4 sounding reference signal based channel characterization with an uplink discrete Fourier transform based precoding for the apparatus having less simultaneously logical uplink antenna ports than logical downlink antenna ports. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive from the network equipment, configuration information for the apparatus to transmit sounding reference signals on configurable logical antenna ports of the apparatus. The configuration information for the apparatus to transmit the sounding reference signals on the configurable logical antenna ports of the apparatus may be configured to cause the apparatus to allocate resources for sounding reference signal transmission on all configurable logical downlink antenna ports. The instructions, when executed with the at least one processor, may further cause the apparatus to: transmit sounding reference signals sequentially on all configurable logical antenna ports of the apparatus. The instructions, when executed with the at least one processor, further cause the apparatus to: transmit sounding reference signals sequentially on respective configurable logical downlink antenna ports. The instructions, when executed with the at least one processor, further cause the apparatus to: transmit at least some sounding reference signals simultaneously on the respective configurable logical downlink antenna ports. The instructions, when executed with the at least one processor, may further cause the apparatus to: transmit multiple input multiple output physical uplink shared channel using at least one of: an uplink precoding, or a transmitted precoding matrix indicator index. The instructions, when executed with the at least one processor, may further cause the apparatus to: transmit a single-layer or multi-layer physical uplink shared channel using an uplink precoding or a transmitted precoding matrix indicator index specified by the network equipment.

[0059] An example method may be provided comprising: sending capability information to a network equipment regarding a capability of an apparatus to support a dynamic antenna port configuration; and receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission. The method may further comprise sending information from the apparatus regarding possible invalid transmitted precoding matrix indicator indexes. The dynamic antenna port configuration may be in regard to a single-layer uplink precoding or a multi-layer uplink precoding. The single-layer or multi-layer uplink precoding may be a single-layer or a multi-layer uplink codebook based precoding. The method may further comprise sending current antenna port configuration information to the network equipment. The current antenna port configuration information may comprise current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output transmission. The current antenna port configuration information may be sent with at least one of: an uplink control information command, or a physical uplink control channel, or a medium access control layer, or a medium access control layer control element. The method may further comprise receiving from the network equipment, for an upcoming uplink multiple input multiple output transmission, at least one of an uplink precoding, or a transmitted precoding matrix indicator index. The precoding information may be configured to be used for the uplink multiple input multiple output transmission on a same frequency and, at a same time, on two of more antenna ports. The apparatus may be configured to support less layers in uplink than in downlink. The apparatus may be configured for a 4x4 sounding reference signal based channel characterization with an uplink discrete Fourier transform based precoding for the apparatus having less simultaneously logical uplink antenna ports than logical downlink antenna ports. The method may further comprise receiving from the network equipment, configuration information for the apparatus to transmit sounding reference signals on configurable logical antenna ports of the apparatus. The configuration information for the apparatus to transmit the sounding reference signals on the configurable logical antenna ports of the apparatus may be configured to cause the apparatus to allocate resources for sounding reference signal transmission on all configurable logical downlink antenna ports. The method may further comprise transmitting sounding reference signals sequentially on all configurable logical antenna ports of the apparatus. The method may further comprise transmitting sounding reference signals sequentially on respective configurable logical downlink antenna ports. The method may further comprise transmitting at least some sounding reference signals simultaneously on the respective configurable logical downlink antenna ports. The method may further comprise transmitting multiple input multiple output physical uplink shared channel using at least one of an uplink precoding, or a transmitted precoding matrix indicator index. The method may further comprise transmitting a single-layer or multi-layer physical uplink shared channel using an uplink precoding or a transmitted precoding matrix indicator index specified by the network equipment.

[0060] An example embodiment may be provided with an apparatus comprising: means for sending capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and mean for receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0061] An example embodiment may be provided with a program storage device readable by an apparatus, tangibly embodying a program of instructions executable with the apparatus for performing operations, the operations comprising: sending capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; and receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.

[0062] An example embodiment may be provided with an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: receive, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determine, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0063] The instructions, when executed with the at least one processor, may further cause the apparatus to: receive information from the user equipment regarding possible invalid precoding matrix indicator indexes. The precoding information may be in regard to a single-layer uplink precoding or a multi-layer uplink precoding. The precoding information may be in regard to single-layer or multi-layer uplink codebook based precoding. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive current antenna port configuration information from the user equipment. The current antenna port configuration information may comprise current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output transmission.

The current antenna port configuration information may be received with an uplink control information command. The instructions, when executed with the at least one processor, may further cause the apparatus to: send to the user equipment, for an upcoming uplink multiple input multiple output transmission, at least one of: an uplink precoding, or a transmitted precoding matrix indicator index. The precoding information may be configured to be used for the uplink multiple input multiple output transmission on a same frequency and, at a same time, for transmitting on different frequencies. The precoding information may be configured for the user equipment to use to support less layers in uplink than in downlink. The instructions, when executed with the at least one processor, may further cause the apparatus to: transmit configuration information to the user equipment, where the configuration information is configured to be used by the user equipment to transmit sounding reference signals on configurable logical antenna ports of the user equipment. The configuration information may be configured to cause the user equipment to allocate resources for sounding reference signal transmission on all configurable logical downlink antenna ports of the user equipment. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive sounding reference signals sequentially from all configurable logical antenna ports of the user equipment. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive sounding reference signals sequentially from respective configurable logical downlink antenna ports of the user equipment. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive multiple input multiple output physical uplink shared channel from the user equipment, where the received channel was configured with at least one of an uplink precoding, or a transmitted precoding matrix indicator index, previously sent by the apparatus to the user equipment. The instructions, when executed with the at least one processor, may further cause the apparatus to: transmit at least some sounding reference signals simultaneously on the respective configurable logical downlink antenna ports. The instructions, when executed with the at least one processor, may further cause the apparatus to: receive multi-layer physical uplink shared channel from the user equipment, where the received channel was configured with at least one of an uplink precoding previously transmitted from the apparatus to the user equipment or a transmitted precoding matrix indicator index specified by the network equipment previously transmitted from the apparatus to the user equipment. The instructions, when executed with the at least one processor, may further cause the apparatus to: determine the precoding information based, at least partially, on current antenna port configuration information received by the apparatus from the user equipment, where the current antenna port configuration information comprises information regarding current logical downlink to logical uplink antenna port relation of a single-layer or multi-layer uplink transmission.

[0064] An example method may be provided comprising: receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission. The method may further comprise receiving information from the user equipment regarding possible invalid precoding matrix indicator indexes. The precoding information may be in regard to a single-layer uplink precoding or a multi-layer uplink precoding. The precoding information may be in regard to single-layer or multi-layer uplink codebook based precoding. The method may further comprise receiving current antenna port configuration information from the user equipment. The current antenna port configuration information may comprise current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output transmission. The current antenna port configuration information may be received with an uplink control information command. The method may further comprise sending to the user equipment, for an upcoming uplink multiple input multiple output transmission, at least one of: an uplink precoding, or a transmitted precoding matrix indicator index. The precoding information may be configured to be used for the uplink multiple input multiple output transmission on a same frequency and, at a same time, for transmitting on different frequencies. The precoding information may be configured for the user equipment to use to support less layers in uplink than in downlink. The method may further comprise transmitting configuration information to the user equipment, where the configuration information is configured to be used by the user equipment to transmit sounding reference signals on configurable logical antenna ports of the user equipment. The configuration information may be configured to cause the user equipment to allocate resources for sounding reference signal transmission on all configurable logical downlink antenna ports of the user equipment. The method may further comprise receiving sounding reference signals sequentially from all configurable logical antenna ports of the user equipment. The method may further comprise receiving sounding reference signals sequentially from respective configurable logical downlink antenna ports of the user equipment. The method may further comprise receiving multiple input multiple output physical uplink shared channel from the user equipment, where the received channel was configured with at least one of: an uplink precoding, or a transmitted precoding matrix indicator index, previously sent by the apparatus to the user equipment. The method may further comprise transmitting at least some sounding reference signals simultaneously on the respective configurable logical downlink antenna ports. The method may further comprise receiving multi-layer physical uplink shared channel from the user equipment, where the received channel was configured with at least one of an uplink precoding previously transmitted from the apparatus to the user equipment or a transmitted precoding matrix indicator index specified by the network equipment previously transmitted from the apparatus to the user equipment. The method may further comprise determining the precoding information based, at least partially, on current antenna port configuration information received by the apparatus from the user equipment, where the current antenna port configuration information comprises information regarding current logical downlink to logical uplink antenna port relation of a single-layer or multi-layer uplink transmission.

[0065] An example embodiment may be provided with an apparatus comprising: means for receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and means for determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0066] An example embodiment may be provided with a program storage device readable by an apparatus, tangibly embodying a program of instructions executable with the apparatus for performing operations, the operations comprising: receiving, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; and determining, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.

[0067] The term "non-transitory," as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. 5 ROM).

[0068] 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 analog and/or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog 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 a mobile phone or sewer, to perform various functions) and (iii) 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." [0069] 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 and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0070] It should be understood that the foregoing description is only illustrative. Various alternatives and modifications can be devised by those skilled in the art. For example, features recited in the various dependent claims could be combined with each other in any suitable combination(s). In addition, features from different embodiments described above could be selectively combined into a new embodiment. Accordingly, the description is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

Claims (25)

1. CLAIMSWhat is claimed is: 1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: send capability information to a network equipment regarding a capability of the apparatus to support a dynamic antenna port configuration; receive, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.
2. 2. The apparatus as claimed in claim 1 where the instructions, when executed with the at least one processor, further cause the apparatus to: send information from the apparatus regarding possible invalid transmitted precoding matrix indicator indexes.
3. 3. The apparatus as claimed in any one of claims 1-2, where the dynamic antenna port configuration is in regard to a single-layer uplink precoding or a multi-layer uplink precoding.
4. 4. The apparatus as claimed in claim 3, where the single-layer or multi-layer uplink precoding is single-layer or multi-layer uplink codebook based precoding.
5. 5. The apparatus as claimed in any one of claims 1-4, where the instructions, when executed with the at least one processor, further cause the apparatus to: send current antenna port configuration information to the network equipment.
6. 6. The apparatus as claimed in claim 5, where the current antenna port configuration information comprises current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output transmission.
7. 7. The apparatus as claimed in any one of claims 5-6, where the current antenna port configuration information is sent with at least one of: an uplink control information command, or a physical uplink control channel, or a medium access control layer, or a medium access control layer control element.
8. 8. The apparatus as claimed in any one of claims 1-7, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive from the network equipment, for an upcoming uplink multiple input multiple output transmission, at least one of an uplink precoding, or a transmitted precoding matrix indicator index.
9. 9. The apparatus as claimed in any one of claims 1-8, where the precoding information is configured to be used for the uplink multiple input multiple output transmission on a same frequency and, at a same time, on two of more antenna ports.
10. 10. The apparatus as claimed in any one of claims 1-9, where the apparatus is configured to support less layers in uplink than in downlink.
11. 11. The apparatus as claimed in any one of claims 1-10, where the apparatus is configured for a 4x4 sounding reference signal based channel characterization with an uplink discrete Fourier transform based precoding for the apparatus having less simultaneously logical uplink antenna ports than logical downlink antenna ports.
12. 12. The apparatus as claimed in any one of claims 1-11, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive from the network equipment, configuration information for the apparatus to transmit sounding reference signals on configurable logical antenna ports of the apparatus.
13. 13. The apparatus as claimed in claim 12, where the configuration information for the apparatus to transmit the sounding reference signals on the configurable logical antenna ports of the apparatus is configured to cause the apparatus to allocate resources for sounding reference signal transmission on all configurable logical downlink antenna ports.
14. 14. The apparatus as claimed in any one of claims 1-13, where the instructions, when executed with the at least one processor, further cause the apparatus to: transmit sounding reference signals sequentially on respective configurable logical downlink antenna ports.
15. 15. The apparatus as claimed in claim 14, where the instructions, when executed with the at least one processor, further cause the apparatus to: transmit at least some sounding reference signals simultaneously on the respective configurable logical downlink antenna ports.
16. 16. The apparatus as claimed in any one of claims 1-15, where the instructions, when executed with the at least one processor, further cause the apparatus to: transmit multiple input multiple output physical uplink shared channel using at least one of: an uplink precoding, or a transmitted precoding matrix indicator index.
17. 17. The apparatus as claimed in any one of claims 1-15, where the instructions, when executed with the at least one processor, further cause the apparatus to: transmit a single-layer or multi-layer physical uplink shared channel using an uplink precoding or a transmitted precoding matrix indicator index specified by the network equipment.
18. 18. A method comprising: sending capability information to a network equipment regarding a capability of an apparatus to support a dynamic antenna port configuration; and receiving, from the network equipment, precoding information, where the precoding information is based, at least partially, upon the capability information of the apparatus to support the dynamic antenna port configuration which was sent to the network equipment, and where the precoding information is configured for use with a multiple input multiple output uplink transmission.
19. 19. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed with the at least one processor, cause the apparatus at least to: receive, from a user equipment, capability information regarding a capability of the user equipment to support a dynamic antenna port configuration; determine, based at least partially on the received capability information, precoding information, where the precoding information is configured to be used by the user equipment with an uplink multiple input multiple output transmission.
20. 20. The apparatus as claimed in claim 19, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive information from the user equipment regarding possible invalid precoding matrix indicator indexes.
21. 21. The apparatus as claimed in any one of claims 19-20, where the precoding information is in regard to a single-layer uplink precoding or a multi-layer uplink precoding.
22. 22. The apparatus as claimed in any one of claims 19-21, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive current antenna port configuration information from the user equipment.
23. 23. The apparatus as claimed in claim 22, where the current antenna port configuration information comprises current logical downlink to logical uplink antenna port relation of uplink multiple input multiple output tran smi ssi on.
24. 24. The apparatus as claimed in any one of claims 19-23, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive multiple input multiple output physical uplink shared channel from the user equipment, where the received channel was configured with at least one of an uplink precoding, or a transmitted precoding matrix indicator index, previously sent by the apparatus to the user equipment.
25. 25. The apparatus as claimed in any one of claims 19-24, where the instructions, when executed with the at least one processor, further cause the apparatus to: receive multi-layer physical uplink shared channel from the user equipment, where the received channel was configured with at least one of an uplink precoding previously transmitted from the apparatus to the user equipment or a transmitted precoding matrix indicator index specified by the network equipment previously transmitted from the apparatus to the user equipment.