HK1247006B - Methods and devices for receiving or transmitting a downlink transmission across a plurality of subframes - Google Patents

Description

Methods and apparatus for receiving or transmitting downlink transmissions across multiple subframes

Technical Field

The present application relates generally to communicating transport blocks in wireless networks, and more particularly to encoding and decoding transport blocks carried by multiple subframes via repetition or bundling.

Background Art

Communication devices may employ one or more interfaces for communicating over wireless networks. Such communication devices can transmit and receive a wide variety of communications. The protocols that support these communications are typically oriented toward supporting the exchange of data generated and/or consumed by humans. However, protocols developed from the perspective of supporting human data communication may not be well suited to supporting communication between machines.

For example, machine-type communications (MTC) can be a significant revenue stream for operators and may have significant potential from an operator's perspective. Furthermore, it can be efficient for operators to use already deployed radio access technologies (e.g., 3GPP LTE) as a competitive radio access technology for efficiently supporting MTC to serve MTC user equipment (UE). Reducing the cost of MTC UEs can also be an important enabler for realizing the concept of the "Internet of Things." For example, MTC UEs used for many applications may require low operating power consumption and may be expected to communicate using infrequent, small burst transmissions. Furthermore, there may be a significant market for machine-to-machine (M2M) use cases for devices deployed deep inside buildings, which may require coverage enhancements compared to the defined LTE cell coverage footprint.

3GPP LTE Release 12 defines UE power saving modes that allow for extended battery life and defines new UE categories that allow for reduced modem complexity. Subsequent releases of 3GPP LTE may further reduce UE costs and provide coverage enhancements. Despite these features, there is still a need for improved wireless communication mechanisms to support a wide variety of devices and the communications they exchange.

Summary of the Invention

A first aspect of the present disclosure provides a method, performed by a communications device, for receiving a downlink transmission across multiple subframes. The method includes receiving control information including a repetition index and receiving a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and wherein the subframe value is indicated by the repetition index within the indicated set.

Thus, a downlink transmission may be received over multiple subframes.

In some examples, the downlink transmission is on a physical downlink shared channel, PDSCH, or the downlink transmission is a transport block.

In some examples, the subframe value indicates the number of subframes used to carry downlink transmissions via repetition or bundling.

In some examples, the method further includes receiving a set indicator separately from receiving the repetition index.

In some examples, receiving the set indicator includes receiving signaling of the set indicator, and receiving the signaling of the set indicator is performed on a less frequent basis than receiving the repetition index.

In some examples, receiving the aggregation indicator includes receiving the aggregation indicator from higher layer signaling.

In some examples, the higher layer signaling of the aggregation indicator is RRC signaling.

In some examples, the control information includes a first field including an indication of a modulation and coding scheme and a second field including a repetition index.

In some examples, the control information is downlink control information DCI.

In some examples, the communication device transmits and/or receives at a reduced radio frequency (RF) bandwidth, or the communication device is a low-cost LC or coverage-enhanced CE communication device.

In some examples, the method further includes decoding the downlink transmission according to the number of subframes used to carry the downlink transmission.

A second aspect of the present disclosure provides a communications device comprising communications circuitry configured to transmit and receive wireless communications, and processing circuitry communicatively coupled to the communications circuitry. The communications circuitry and the processing circuitry are configured to receive downlink transmissions across multiple subframes by receiving control information including a repetition index and a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication circuitry and processing circuitry are configured to receive a downlink transmission on a physical downlink shared channel (PDSCH), or wherein the downlink transmission is a transport block.

In some examples, the subframe value indicates the number of subframes used to carry downlink transmissions via repetition or bundling.

In some examples, the control information is downlink control information DCI.

In some examples, the communication circuit is configured to transmit and/or receive at a reduced radio frequency (RF) bandwidth, or the communication device is a low-cost LC or coverage-enhanced CE communication device.

In some examples, the processing circuit is configured to decode the downlink transmission according to the number of subframes used to carry the downlink transmission.

A third aspect of the present disclosure provides a method in a communication device for transmitting a downlink transmission across multiple subframes. The method includes transmitting control information including a repetition index and transmitting a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and wherein the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication device is a base station.

In some examples, the method further includes transmitting the set indicator separately from transmitting the repeat index.

In some examples, transmitting the set indicator includes signaling that transmits the set indicator on a less frequent basis than transmitting the repetition index.

In some examples, the transmit set indicator includes the transmit set indicator as higher layer signaling.

In some examples, transmitting the control information includes transmitting a first field including an indication of a modulation and coding scheme and a second field including a repetition index.

A fourth aspect of the present disclosure provides a communication device comprising communication circuitry configured to send and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The processing circuitry is configured to transmit a downlink transmission across a plurality of subframes via the communication circuitry, and to transmit signaling via the communication circuitry, the signaling comprising: control information comprising a repetition index; and a set indicator for indicating one of a plurality of sets, wherein each set comprises a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and wherein the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication device is a base station.

In some examples, the processing circuit is configured to transmit the set indicator separately from the repeat index.

In some examples, the processing circuit is configured to transmit signaling including the set indicator on a less frequent basis than transmitting signaling including the repetition index.

In some examples, the processing circuit is configured to transmit the aggregation indicator as higher layer signaling.

In some examples, the processing circuit is configured to transmit control information including a first field indicating a modulation and coding scheme and a second field including a repetition index.

A further aspect of the present disclosure provides a computer program comprising instructions which, when executed by at least one processor of an apparatus, cause the apparatus to carry out the method as claimed in any example.

A further aspect of the present disclosure provides a carrier embodying the computer program, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG1 illustrates an example network according to examples of the present disclosure;

FIG2 illustrates a communication device according to an example of the present disclosure;

FIG3 illustrates a method of a communication device according to an example of the present disclosure;

FIG4 shows a method of another communication device according to an example of the present disclosure,

FIG5 illustrates a method of a communication device according to another example of the present disclosure; and

FIG6 illustrates a method of another communication device according to another example of the present disclosure.

DETAILED DESCRIPTION

For simplicity and illustrative purposes, the present disclosure is described primarily with reference to its exemplary embodiments. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be readily apparent to one of ordinary skill in the art that the present invention can be practiced without limitation to these specific details. In this description, well-known methods and structures have not been described in detail to avoid unnecessarily obscuring the present invention. For example, although the present disclosure will generally refer to communication devices as UEs herein, other wireless communication devices may be used in accordance with one or more embodiments.

FIG1 illustrates an example communications apparatus 100 in which embodiments relate to transmitting or signaling information indicating the number of subframes used for transmission via repetition or bundling. Aspects relate to determining the number of subframes used to carry a transmission via repetition or bundling. A transmission may be a transport block carried across multiple subframes via repetition or bundling. Communications network 100 may be implemented using one or more radio access technologies, such as, for example, LTE, LTE-Advanced, WCDMA, GSM, or any 3GPP or other radio access technology.

The communication network 100 includes network communication devices, such as, for example, a base station 103 serving a cell 101. The base station 103 may be a base station such as a radio base station, a NodeB, an evolved NodeB (eNB), depending on the technology and terminology used, or any other network element capable of communicating with one or more user equipments 109 being present in the cell 101 over a radio carrier 102. The radio carrier 102 may also be referred to as a carrier, a radio channel, a channel, a communication link, a radio link, or a link.

User equipment 105 present within cell 101 and served by base station 103 can in this case communicate with base station 103 via radio carrier 102. Data streams are conveyed between base station 103 and user equipment 109 via radio channel 102. User equipment may alternatively be referred to as a communication device.

According to one or more embodiments, a communications device may transmit and/or receive at a reduced radio frequency (RF) bandwidth. For example, the communications device may transmit and/or receive using a different RF bandwidth than the baseband bandwidth. Furthermore, the communications device may make a modulation and coding scheme (MCS) determination that allows for cross-subframe repetition. Thus, according to one or more embodiments, MCS determination and transfer block size (TBS) determination methods may be improved over existing systems. For example, support for a reduced UE RF bandwidth of 1.4 MHz in both the downlink and uplink may be introduced within any system bandwidth. Furthermore, one or more embodiments may enable transport block reception using cross-subframe repetition or bundling. According to one or more embodiments, the introduction of this reduced UE RF bandwidth support may achieve a reduction in UE costs and may be particularly relevant to low-cost (LC) and coverage-enhanced (CE) UEs. One or more embodiments may generally discuss solutions for supporting the exchange of transport blocks between wireless devices in a wireless network. The communications device may be, for example, an MTC UE. One or more embodiments may additionally or alternatively include a communication apparatus that may be limited to a radio frequency (RF) bandwidth not exceeding 1.4 MHz in a long term evolution (LTE) system having wider system bandwidth available.

Communication of transport blocks may require modulation and coding scheme (MCS) determination. When transport blocks are carried across multiple subframes without repetition or bundling, the receiving UE may use a modulation order (Q m ) of 2 if the downlink control information (DCI) cyclic redundancy check (CRC) is scrambled by the paging radio network temporary identifier (P-RNTI), random access RNTI (RA-RNTI), or system information RNTI (SI- _RNTI ). Otherwise, when higher-order modulation 256-quadrature amplitude modulation (QAM) is not enabled, the communication device may use a table, such as Table 1 below, to determine the modulation order (Q _m ) used, for example, in the physical downlink shared channel. Table 1 shows a modulation and TBS index table for the physical downlink shared channel (PDSCH).

For transport block size (TBS) determination, for 0 ≤ I _MCS ≤ 28, the communication device may first determine the TBS index (I _TBS ) using I _MCS and Table 1. For transport blocks that are not mapped to two or more layers of spatial multiplexing, the TBS may be given by the (I _TBS , N _PRB ) entry in Table 2. Table 2 shows a transport block size table (size 34 x 110), where N _PRB ≤ 6 PRBs.

Table 1: Modulation and TBS index for the Physical Downlink Shared Channel (PDSCH)

Table 2: Transport block size table (size 34 x 110), where N _PRB ≤ 6 PRB

One or more embodiments of the present disclosure include methods, apparatus, systems, and computer program products for providing, for example, MCS and TBS determination for LTE communications. For example, embodiments may include improvements over existing LTE Release 13 LC/CE UEs. For example, one or more link adaptation mechanisms for LC/CE UEs may be supported, in which repetition or bundling is performed across several subframes. For example, one or more embodiments may support UE operation across a wide range of signal-to-interference-plus-noise ratio (SINR) conditions. For example, under high SINR conditions, a UE may use modulation levels up to 64-QAM and not require repetition/bundling across subframes. For another example, under medium SINR conditions, a UE may not be able to utilize high-level modulation levels like 64-QAM (i.e., may only use low-level modulation levels such as Quadrature Phase Shift Keying (QPSK) and 16-QAM) and may require a low level of repetition/bundling across subframes. For yet another example, under low SINR conditions, a UE may only use the lowest level modulation level (e.g., QPSK) and require a high level of repetition/bundling across subframes.

One or more embodiments may relate to a communication device where multiple repetitions across subframes are necessary for low-cost (LC) and coverage-enhanced (CE) UEs. The number of repetitions may, for example, be as high as ~300 subframes to reach the UE with an SINR 15 dB lower than normal cell edge. Providing protection for UEs in normal coverage, where they need to use MCS tables and TBS determination mechanisms similar to those used in legacy systems, may also be advantageous. Thus, the various link adaptation methods proposed herein can flexibly provide a wide range of combinations of {TBS, modulation order, code rate}, where the code rate includes not only parameters within a subframe but also the number of repetitions/bundling across subframes. Here, the repetition indicator simply replicates the code bits associated with the same transport block (TB) from subframe to subframe, while the bundling indicator allows the code bits associated with the same transport block (TB) to vary from subframe to subframe due to a rate matching mechanism.

One or more of the MCS and TBS determination methods for LC/CE UEs described herein may satisfy the following Release 13 MTC conditions: (a) the maximum transmit and receive bandwidth may be 1.4 MHz (or 6 physical resource blocks (PRBs)); (b) the maximum TBS that a UE may be required to receive in a PDSCH may be approximately 1000 bits; and (c) if a large number of repetitions are required, it may be preferable to use more PRBs (e.g., 6 PRBs) to reduce the number of subframes required for repetition or bundling.

According to one embodiment, the enhanced physical downlink control channel defines and carries the first and second (i.e., two) DCI fields. One of the DCI fields may contain a 5-bit MCS and redundancy version field, which provides the MCS index I _MCS . I _MCS is used to look up the modulation order Q _m and the TBS index I _TBS . The other field may be a repetition index (alternatively called a subframe index). The repetition (i.e., subframe) index may be optional. When the repetition index is absent in the DCI, it may indicate that no repetition/bundling occurs across subframes (i.e., N _rep,pdsch,i = 1). When N _rep,pdsch,i = 1, it may indicate that the PDSCH is transmitted only within a single subframe (i.e., no repetition occurs across subframes). When the repetition index field is present in the DCI, the repetition index I _rep,pdsch may be used to look up the number of PDSCH repetitions using a table. As an example, the 2-bit repetition index I _rep,pdsch and the table are shown in Table 3. Table 3 shows a repetition (i.e., subframe) table for the PDSCH. In the table, {N _rep,pdsch,0 , N _rep,pdsch,1 , N _rep,pdsch,2 , N _rep,pdsch,3 } is a set of integer numbers (≥1) that indicates the number of subframes used to carry a specified PDSCH transmission via repetition or bundling. In some examples, the repetition is indicated by a combination of a set and an index within the set. The set can be signaled separately from the index, for example on a less frequent basis. The set S _rep ={N _rep,pdsch,i } (i=0, 1, 2, 3) can be provided by higher layer signaling (e.g., RRC signaling). The set can be signaled semi-statically. Several sets of S _rep can be defined, for example, one set per coverage enhancement level. Higher layer signaling (e.g., RRC signaling) can indicate j, i.e., which set S _rep (j) should be used when looking up Table 1 with I _rep,pdsch . For example:

For UEs with medium to high SINR (e.g., normal-cost UEs at the cell edge),

For UEs with low to medium SINR (e.g., UEs with 3-5dB coverage enhancement),

For UEs with low SINR (e.g., UEs with 5-10dB coverage enhancement),

For UEs with very low SINR (e.g., UEs with 10-15dB coverage enhancement), .

The set S _rep (j) may be provided specifically for PDSCH transmission. Alternatively, the set S _rep (j) may be provided implicitly, for example, via a set on the repetition level of the EPDCCH (eg, the repetition level that the EPDCCH should use).

According to one or more embodiments, the use of repeated index fields results in a relatively larger DCI size.

Table 3: Repetition (ie, subframe) table for PDSCH

PDSCH transmission can be considered an example of a downlink transmission. Alternatively, instead of including a repetition index field in the DCI, a field indicating the number of repetitions used can be embedded in the 5-bit field "Modulation and Coding Scheme and Redundancy Version." The MCS and Redundancy Version fields can be modified, for example, for LC/CE UEs. According to one or more embodiments, this embedding can result in a relatively smaller DCI than if a separate repetition index were included, as described above. This embedding allows the use of the same 5-bit field to carry both the modulation and coding scheme and the repetition information.

Some embodiments may include some LC/CE UEs that may not be required to receive TBSs exceeding 1000 bits. Therefore, a normal TBS table may include entries that may not be useful to certain UEs (e.g., because LC/CE UEs are not required to receive TBSs exceeding 1000 bits, TBS entries greater than 1000 bits may be considered "empty entries"). Table 4 below is an example of a table including these so-called "empty entries" (note that the "empty entries" are highlighted). Table 4 shows a TBS table with "empty entries". Instead of providing indices that are not applicable, these indices may instead be used to provide information about the number of repetitions used. Because different numbers of empty entries may be available for different N _PRBs , different N _PRB values may require different MCS mapping tables. An example involving a field indicating the number of repetitions used embedded in the MCS and redundancy version fields may be to construct a set of MCS mapping tables as shown in Tables 5-10.

Table 4: TBS table with "empty entries"

In one embodiment, the number of repetitions is fixed and predefined in the specification. This is used in Tables 5-8, where the number of PRBs used for transport block transmission is small: _NPRB = 1, 2, 3, 4.

In another embodiment, the number of repetitions is not fixed and a value provided by higher layers (e.g., RRC signaling) is used. This is used in Tables 9-10, where the number of PRBs used for TB transmission is larger, e.g., N _PRB = 5, 6. Specifically, the number of repetitions provided by higher layers may reuse the set of repetition levels provided to the Physical Downlink Control Channel (PDCCH) for LC/CE UEs. Let {N _rep,EPDCCH,0 , N _rep,EPDCCH,1 , N rep,EPDCCH _,2 , N _rep,EPDCCH,3 } be, for example, the number of repetitions across the subframes configured for the EPDCCH for a given UE. The MCS table for the PDSCH for MTC UEs may be defined using the repetition level for a specific control channel (e.g., EPDCCH). Note that one or more embodiments may define a set of repetition levels specifically for the PDSCH, and not via N _rep,EPDCCH,i for the EPDCCH.

In the table, some of the example MCS indices I _MCS are mapped to a combination of {I _TBS , N _rep,pdsch }, where I _TBS is used to find the transport block size and N _rep,pdsch is the number of subframes used to carry PDSCH transmissions via repetition/bundling. For example, in Table 6, I _MCS = 26 indicates the use of a modulation order Q _m = 2 (i.e., QPSK) and a combination of {I _TBS = 2, N _rep,pdsch = 4}. In some examples, the field previously used to indicate the TBS index I _TBS indicates both the TBS index and the number of repetitions. In some examples, the field previously used to indicate the TBS index I _TBS indicates only the number of repetitions.

In Tables 5-10, each table contains reserved entries. The reserved values can be used during PDSCH retransmissions, where they can define the number of repetitions/bundles across the time that the PDSCH retransmissions should use. Table 5 shows an MCS table for NPRB=1. For example, in Table 5, I _MCS =30 can indicate that for PDSCH retransmissions, the modulation order is 2 (i.e., QPSK) and the number of repetitions/bundles across subframes is N _rep,pdsch =4 (i.e., 4 subframes can be used in the retransmission of a given transport block). Examples of the present disclosure are shown in Table 5 for TBS index values corresponding to MCS indices 27 to 31, in Table 6 for TBS index values corresponding to MCS indices 22 to 31, in Table 7 for TBS index values corresponding to MCS indices 17 to 31, in Table 8 for TBS index values corresponding to MCS indices 14 to 31, in Table 9 for TBS index values corresponding to MCS indices 12 to 31, and in Table 10 for TBS index values corresponding to MCS indices 10 to 31. Table 6 shows an MCS table for NPRB = 2. Table 7 shows an MCS table for NPRB = 3. Table 8 shows an MCS table for NPRB = 4. Table 9 shows an MCS table for NPRB = 5. Table 10 shows an MCS table for NPRB = 6.

Although TBS index values are conventionally assigned to these fields, it has been recognized that the corresponding transport block sizes exceed the size that can be used and can therefore be reused to carry (or additionally carry) repetition information.

For Tables 5-10, I _TBS = 9 and I _TBS = 15 appear only once in each table, rather than twice as in, for example, legacy systems. This can be used to increase the number of values that can be used to indicate the combination of {I _TBS = 2, N _rep,pdsch = 4}.

Table 5: MCS table for NPRB=1

Table 6: MCS table for NPRB=2

Table 7: MCS table for NPRB=3

Table 8: MCS table for NPRB=4

Table 9: MCS table for NPRB=5

Table 10: MCS table for NPRB=6

Furthermore, one or more embodiments may include the example hardware depicted in FIG. 2 . Communication device 100 includes processing circuitry 820, which is communicatively coupled to memory circuitry 810 and communication circuitry 860, for example, via one or more buses. Processing circuitry 820 may include one or more microprocessors, microcontrollers, hardware circuits, discrete logic circuits, hardware registers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), or combinations thereof. For example, processing circuitry may be programmable hardware capable of executing machine instructions stored as machine-readable computer program 850 in memory circuitry 810. Memory circuitry 810 in various embodiments may include any non-transitory machine-readable medium known or developed in the art, including, but not limited to, magnetic media (e.g., floppy disks, hard drives, etc.), optical media (e.g., CD-ROMs, DVD-ROMs, etc.), solid-state media (e.g., SRAM, DRAM, DDRAM, ROM, PROM, EPROM, flash memory, solid-state drives, etc.), or the like.

The communication circuit 860 can be configured to send and receive wireless communications via a wireless communication network. For example, the communication circuit 860 can be a transceiver. Depending on the embodiment, the communication circuit 860 can include different output circuits 830 and input circuits 840. The output circuit 830 can be configured to send communication signals via the wireless communication network. For example, the output circuit 830 can be a transmitter. The input circuit 840 can be configured to receive communication signals via the wireless communication network. For example, the input circuit 840 can be a receiver. When implemented as different respective components, the output circuit 830 and the input circuit 840 can be communicatively coupled to each other, or can communicate with each other via the processing circuit 820.

According to one embodiment, the processing circuit 820 is configured to determine the number of subframes used to carry the transport block via repetition or bundling, and to decode the transport block according to the determined number of subframes.

According to various embodiments, the processing circuit 820 is configured to transmit the transport block across multiple subframes via repetition or bundling via the communication circuit 860 and transmit downlink control information (DCI) via the communication circuit 860 for decoding the transport block.

3 illustrates a method 900 performed by a communications device for receiving a downlink transmission across multiple subframes. In some examples, the communications device is a user equipment. The method 900 includes, at 901, receiving control information including a repetition index.

The method 900 further includes receiving 902 a set indicator for indicating one of a plurality of sets. Each set includes a plurality of subframe values.

In some examples, method aspects 901 and 902 can be performed in any order. In some examples, receiving 902 the set indicator can be separate from receiving 901 the repetition index. In some examples, receiving 902 the set indicator includes receiving signaling of the set indicator, and the signaling of the set indicator is performed on a less frequent basis than receiving 901 the repetition index.

In some examples, receiving 902 the aggregation indicator includes receiving the aggregation indicator from higher layer signaling. In some examples, the higher layer signaling of the aggregation indicator is RRC signaling.

In 903, the number of subframes used to carry downlink transmissions is indicated by the subframe value, and wherein the subframe value is indicated by a repetition index within the indicated set.

In some examples, at 903, the communications device determines the number of subframes based on the indicated subframe value (indicated by the repetition index within the indicated set). In some examples, the subframe value identified by the set and the repetition index is the number of subframes over which downlink transmissions (e.g., PDSCH transmissions) are received. In some aspects, 903 can be viewed as using the repetition index to select one of the subframe values from the indicated set. The selected subframe value indicates the number of subframes used to carry the downlink transmission. In some aspects, the number of subframes can be viewed as being determined by the repetition index.

In some examples, method 900 optionally includes receiving 904 a downlink transmission according to the signaled number of subframes.

FIG4 illustrates a method 950 in a communications device for transmitting a downlink transmission across multiple subframes. In some examples, the communications device is a base station, such as an eNB. The method 950 includes transmitting 951 control information including a repetition index. The method 950 further includes transmitting 952 a set indicator indicating one of a plurality of sets. Each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set.

In some examples, method 950 optionally includes transmitting 953 a downlink transmission according to a signaled number of subframes.

In some aspects, the repetition index is used to select one of the subframe values from the indicated set, and the selected subframe value indicates the number of subframes used to carry downlink transmissions.

In some examples, transmitting the set indicator 952 is separate from transmitting the repetition index 951. In some examples, transmitting 952 the set indicator includes signaling that transmits the set indicator on a less frequent basis than transmitting the repetition index 951. In some examples, transmitting 952 the set indicator includes transmitting the set indicator as higher layer signaling.

In some examples, transmitting 951 control information includes transmitting a first field including an indication of a modulation and coding scheme and a second field including a repetition index.

abbreviation:

3GPP Third Generation Partnership Project

BW Bandwidth

DL Downlink

DCI Downlink Control Information

eNB Evolved Node B

FDD Frequency Division Duplex

LTE Long Term Evolution

MTC Machine Type Communication

EPDCCH Enhanced Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PDCCH Physical Downlink Control Channel

PRB Physical Resource Block

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RB Resource Block

TDD Time Division Duplex

UE User Equipment

UL Uplink

RRC Radio Resource Control

The present invention may of course be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention.The present embodiments are to be considered in all respects as illustrative and not restrictive.

Those skilled in the art will appreciate that the embodiments herein generally include a method implemented by a communication device (e.g., a low-cost or coverage-enhanced MTC device) in a wireless communication network. The method is for decoding a transport block (e.g., received by the device via a PDSCH in an LTE network). The method may include determining a number of subframes used to carry the transport block via repetition or bundling, and decoding the transport block based on the determined number of subframes, for example, by determining a transport block size (TBS) and a modulation and coding scheme (MCS) for the transport block based on the determined number of subframes.

In at least some embodiments, this entails receiving downlink control information (DCI) over a control channel (e.g., LTE DCI over EPDCCH in LTE) and determining the number of subframes used to carry the transport block via repetition or bundling based on the received information.

In one or more embodiments, for example, determining the number of subframes based on the DCI includes referencing a subframe table using an index or field within the DCI (e.g., referred to as a "subframe index") that indicates the number of subframes used to carry a transport block via repetition or bundling. In some aspects, the DCI field provides an indicator for repetition or bundling across subframes. In at least one embodiment, an apparatus receives signaling (e.g., RRC signaling) via a wireless communication network and populates the subframe table with a set of subframe values received via the signaling, wherein the signaling includes a set of subframe values indicating a plurality of potential numbers (e.g., sets) of subframes used to carry a transport block via repetition or bundling. In this case, referencing the subframe table using the subframe index includes selecting one of the set of subframe values within the subframe table using the subframe index.

In one or more embodiments, therefore, the subframe table may be dynamically populated with different sets of subframe values at different times for different types of devices, for different cost or coverage requirements for different devices, or any combination thereof.

In some embodiments, the signaling explicitly indicates a set of subframe values. Alternatively, the signaling may implicitly indicate the set. For example, in one embodiment, the signaling is control information regarding the repetition level of a different channel (e.g., the enhanced physical downlink control channel in LTE). In this case, the repetition level applicable to the received transport block is implicit in or inherited from the repetition level used to receive the different transmissions.

Instead of using a dedicated subframe index and subframe table as described above, one or more other embodiments herein require using a modulation and coding scheme (MCS) index within the DCI to reference an MCS table that indicates each of the modulation order, transport block size index, and/or number of subframes to determine the number of subframes. For example, one or more MCS indices in the MCS table may be mapped to a combination of modulation order, TBS index, and number of subframes. In at least some embodiments, only a portion of the MCS indices in the MCS table are mapped to such a combination, while other MCS indices are mapped only to a combination of modulation order and TBS index (without indicating the number of subframes). The portion of the MCS index mapped to the combination including the number of subframes may include, for example, an index that is applicable or required for some devices or situations in the network, but is not specifically applicable or required for that device or situation. In some examples, the MCS index is transmitted and received in the DCI, with the MCS index having multiple possible values. One or more values of the MCS index provide an indication of only the modulation order and transport block size (i.e., without any duplication or bundling across subframes). Different one or more values of the MCS index indicate repetition or bundling across subframes. In some aspects, the MCS index value also indicates the modulation order. Optionally, the MCS index value also indicates the transport block size. The MCS index value used to indicate repetition or bundling across subframes may correspond to a transport block size that exceeds a threshold (e.g., 1000) and is identified as not being used in certain types of communications (e.g., communications as described). Thus, a single MCS index value (5 bits) is capable of indicating the modulation order, the transport block size, and only in a portion of the value, the number of repetitions or bundling across subframes. In some aspects, the transport block size may be defined in association with the number of PRBs. The MCS index may indicate repetition or bundling across subframes associated with the number of PRBs.

Embodiments herein also include a method for encoding a transport block implemented by a communication device (e.g., a base station (e.g., an eNB)) in a wireless communication network. The method includes transmitting the transport block across multiple subframes via repetition or bundling (e.g., via the PDSCH in LTE). The method also requires transmitting signaling (e.g., as RRC signaling or via the EPDCCH in LTE) for decoding the transport block indicating the number of subframes and/or a potential set of subframes over which the transport block is transmitted via repetition or bundling. The transmitted signaling indicating the number of subframes over which the transport block is transmitted via repetition or bundling can, in any example, be as described.

In some embodiments, transmitting the signaling comprises transmitting a subframe index within downlink control information (DCI).The subframe index (or field) when used as a reference into a subframe table indicates the number of subframes in the plurality of subframes.

Alternatively or additionally, the signaling may indicate a set of subframe values indicating a plurality of potential numbers of subframes used to carry a transport block via repetition or bundling. In this case, the subframe index in the signaling may indicate one of the set of subframe values.

In some embodiments, transmitting the signaling includes transmitting the signaling via control information regarding a repetition level of an enhanced physical downlink control channel.

Alternatively or additionally, transmitting the DCI comprises transmitting a modulation and coding scheme (MCS) index within the DCI, the DCI indicating each of: a modulation order, a transport block size index, and a number of subframes in the plurality of subframes when the MCS index is used as a reference into an MCS table.

One or more embodiments herein also include corresponding communication devices, computer programs, and computer program products.

A communication device may include, for example, communication circuitry configured to send and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The processing circuitry may be configured to determine the number of subframes used to carry a transport block via repetition or bundling, and to decode the transport block based on the determined number of subframes. The device may be otherwise configured as described above.

According to other embodiments, a communication device includes communication circuitry configured to send and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The processing circuitry is configured to transmit a transport block across multiple subframes via repetition or bundling via the communication circuitry, and to transmit signaling via the communication circuitry for decoding the transport block. The device may be configured in other ways as described above.

The computer program comprises instructions which, when executed by at least one processor of an apparatus, cause the apparatus to perform any of the methods herein.

The carrier embodies the computer program above, wherein the carrier is one of an electronic signal, an optical signal, a radio signal or a computer-readable storage medium.

One aspect of the present disclosure provides a method performed by a communications device for receiving a downlink transmission across multiple subframes. The method includes receiving control information containing a repetition index and receiving a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set. Thus, the downlink transmission can be received across multiple subframes.

In some examples, the downlink transmission is on a physical downlink shared channel (PDSCH), or the downlink transmission is a transport block. In some examples, the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. In some examples, the method further includes receiving a set indicator separately from receiving a repetition index. In some examples, receiving the set indicator includes receiving signaling of the set indicator, and the signaling of receiving the set indicator is performed on a less frequent basis than receiving the repetition index. In some examples, receiving the set indicator includes receiving the set indicator from higher layer signaling. In some examples, the higher layer signaling of the set indicator is RRC signaling.

In some examples, the control information includes a first field and a second field, the first field including an indication of a modulation and coding scheme, and the second field including a repetition index. In some examples, the control information is downlink control information (DCI). In some examples, the communication device transmits and/or receives at a reduced radio frequency (RF) bandwidth, or the communication device is a low-cost (LC) or coverage-enhanced (CE) communication device. In some examples, the method further includes decoding the downlink transmission based on the number of subframes used to carry the downlink transmission.

Another aspect of the present disclosure provides a communications device comprising communications circuitry configured to transmit and receive wireless communications, and processing circuitry communicatively coupled to the communications circuitry. The communications circuitry and processing circuitry are configured to receive downlink transmissions across multiple subframes by receiving control information including a repetition index and a set indicator indicating one of a plurality of sets, each of which includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication circuitry and the processing circuitry are configured to receive a downlink transmission on a physical downlink shared channel (PDSCH), or wherein the downlink transmission is a transport block. In some examples, the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. In some examples, the control information is downlink control information (DCI).

In some examples, the communication circuit is configured to receive the aggregation indicator separately from the repetition index. In some examples, the communication circuit is configured to receive the aggregation indicator on a less frequent basis than the repetition index. In some examples, the communication circuit and the processing circuit are configured to receive the aggregation indicator from higher layer signaling. In some examples, the higher layer signaling of the aggregation indicator is RRC signaling. In some examples, the communication circuit is configured to receive control information comprising a first field and a second field, the first field comprising an indication of a modulation and coding scheme and the second field comprising the repetition index. In some examples, the control information is downlink control information (DCI).

In some examples, the communication circuitry is configured to transmit and/or receive at a reduced radio frequency (RF) bandwidth, or the communication device is a low-cost LC or coverage-enhanced CE communication device. In some examples, the processing circuitry is configured to decode the downlink transmission based on the number of subframes used to carry the downlink transmission.

Another aspect of the present disclosure provides a method in a communications device for transmitting a downlink transmission across multiple subframes. The method includes transmitting control information including a repetition index and transmitting a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and wherein the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication device is a base station. In some examples, the method further includes transmitting the set indicator separately from transmitting the repetition index. In some examples, transmitting the set indicator includes signaling that transmits the set indicator on a less frequent basis than transmitting the repetition index.

In some examples, transmitting the set indicator includes transmitting the set indicator as higher layer signaling. In some examples, transmitting the control information includes transmitting a first field including an indication of a modulation and coding scheme and a second field including a repetition index.

In some examples, the downlink transmission is on a physical downlink shared channel (PDSCH), or the downlink transmission is a transport block. In some examples, the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. In some examples, higher-layer signaling of the aggregation indicator is RRC signaling. In some examples, the control information is downlink control information (DCI). In some examples, the communication device transmits and/or receives with a reduced radio frequency (RF) bandwidth, or the communication device communicates with a low-cost (LC) or coverage-enhanced (CE) communication device.

Another aspect of the present disclosure provides a communication device comprising communication circuitry configured to send and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The processing circuitry is configured to transmit a downlink transmission across a plurality of subframes via the communication circuitry, and to transmit signaling via the communication circuitry, the signaling comprising: control information including a repetition index; and a set indicator indicating one of a plurality of sets, wherein each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and wherein the subframe value is indicated by the repetition index within the indicated set.

In some examples, the communication device is a base station. In some examples, the processing circuit is configured to transmit the aggregation indicator separately from the repetition index. In some examples, the processing circuit is configured to transmit signaling including the aggregation indicator less frequently than signaling including the repetition index. In some examples, the processing circuit is configured to transmit the aggregation indicator as higher layer signaling. In some examples, the processing circuit is configured to transmit control information comprising a first field indicating a modulation and coding scheme and a second field including the repetition index.

In some examples, the communication circuit is configured to transmit a downlink transmission on a physical downlink shared channel (PDSCH), or the downlink transmission is a transport block. In some examples, the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. In some examples, the higher layer signaling of the aggregation indicator is RRC signaling.

In some examples, the control information is downlink control information (DCI). In some examples, the communication device transmits and/or receives with a reduced radio frequency (RF) bandwidth, or the communication device communicates with a low-cost (LC) or coverage-enhanced (CE) communication device.

A further aspect of the present disclosure provides a computer program comprising instructions which, when executed by at least one processor of an apparatus, cause the apparatus to carry out the method as described in the examples.

A further aspect of the present disclosure provides a carrier embodying the computer program as described in any example, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium.

In some aspects, a method performed by a communications device for receiving a downlink transmission across multiple subframes includes receiving control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

In some examples, the MCS index indicates at least one of a transport block size index, a modulation order, and a number of subframes.

In some examples, the MCS index references an MCS table, and only a portion of the MCS index in the MCS table is mapped to at least the number of subframes, and only another portion of the MCS index is mapped to a transport block size index without indicating the number of subframes.

In some aspects, the transport block size is defined by a transport block size index in association with the number of physical resource blocks (PRBs).

In some aspects, the subframe number indicates the number of subframes used to carry downlink transmissions via repetition or bundling.

In some examples, the downlink transmission is on a physical downlink shared channel (PDSCH). In some examples, the downlink transmission is a transport block.

Another example provides a communication device comprising communication circuitry configured to transmit and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The communication circuitry and the processing circuitry are configured to receive downlink transmissions across multiple subframes by receiving control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

In this example, the communication device may be a user equipment.

Another example provides a communication device comprising communication circuitry configured to transmit and receive wireless communications, and processing circuitry communicatively coupled to the communication circuitry. The processing circuitry is configured to transmit a downlink transmission across a plurality of subframes via the communication circuitry, and to transmit signaling via the communication circuitry, the signaling comprising control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

Another example provides a method in a communications device for transmitting a downlink transmission across multiple subframes, the method comprising: transmitting control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

In this example, the communication device may be a base station.

In some examples, the MCS index indicates at least one of a transport block size index, a modulation order, and a number of subframes.

In some examples, the MCS index references an MCS table, and only a portion of the MCS index in the MCS table is mapped to at least the number of subframes, and only another portion of the MCS index is mapped to a transport block size index without indicating the number of subframes.

In some aspects, the transport block size is defined by a transport block size index in association with the number of physical resource blocks (PRBs).

In some aspects, the subframe number indicates the number of subframes used to carry downlink transmissions via repetition or bundling.

In some examples, the downlink transmission is on a physical downlink shared channel (PDSCH). In some examples, the downlink transmission is a transport block.

FIG5 illustrates a method 970 performed by a communications device for receiving a downlink transmission across multiple subframes. In some examples, the communications device is a user equipment (UE). The method 970 includes receiving control information at 971, the control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

Optionally at 972, the communications device decodes the transmission using the subframe number.

FIG6 illustrates a method 980 for transmitting a downlink transmission across multiple subframes in a communications device. In some examples, the communications device is a base station, such as an eNB. The method 980 includes transmitting 981 control information including a modulation and coding scheme (MCS) index. The MCS index indicates at least one of a transport block size index and a subframe number (alternatively referred to as a subframe value). The subframe number indicates the number of subframes used to carry the downlink transmission.

In some examples, method 980 optionally includes transmitting 982 a downlink transmission according to the signaled number of subframes.

Another aspect of the present disclosure provides a method performed by a communication device for receiving a downlink transmission across multiple subframes. The method includes receiving control information including a repetition index and receiving a set indicator indicating one of a plurality of sets, where each set includes a plurality of subframe values. The repetition index is used to select one of the subframe values from the indicated set, where the selected subframe value indicates the number of subframes used to carry the downlink transmission. Aspects of the present disclosure may provide a corresponding transmission performed by a communication device (e.g., a base station), and a communication device according to any example.

In some examples, receiving the set indicator may be considered as obtaining the set indicator. In some aspects, the present disclosure may be defined without reference to receiving or obtaining the set indicator. The set indicator may be used by a communication device without reference to receiving or obtaining the set indicator.

Claims (30)

1. A method performed by a communication device for receiving downlink transmissions across multiple subframes, comprising: Receive control information including duplicate indices; Receive a set indicator for indicating one of a plurality of sets, where each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set. 2. The method claimed in claim 1, wherein the downlink transmission is on the Physical Downlink Shared Channel (PDSCH) or the downlink transmission is a transport block. 3. The method claimed in claim 1 or 2, wherein the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. 4. The method claimed in any one of claims 1 and 2, further comprising receiving the set indicator separately from receiving the duplicate index. 5. The method claimed in any one of claims 1 and 2, wherein receiving the set indicator includes signaling for receiving the set indicator, and The frequency of receiving the signaling for the set indicator is less than the frequency of receiving the signaling for the duplicate index. 6. The method claimed in any one of claims 1 and 2, wherein receiving the set indicator includes receiving the set indicator from higher-layer signaling. 7. The method claimed in claim 6, wherein the higher-layer signaling of the set indicator is RRC signaling. 8. The method claimed in any one of claims 1 and 2, wherein the control information includes a first field and a second field, the first field including an indication of modulation and coding scheme, and the second field including the repeat index. 9. The method claimed in any one of claims 1 and 2, wherein the control information is downlink control information (DCI). 10. The method claimed in any one of claims 1 and 2, wherein the communication device transmits and/or receives with reduced radio frequency (RF) bandwidth, or the communication device is a low-cost LC or coverage-enhanced CE communication device. 11. The method claimed in any one of claims 1 and 2, further comprising decoding the downlink transmission based on the number of subframes used to carry the downlink transmission. 12. A communication apparatus comprising a communication circuit configured to transmit and receive wireless communications, and a processing circuit communicationally coupled to the communication circuit, wherein the communication circuit and the processing circuit are configured to receive downlink transmissions across a plurality of subframes by: Receive control information including duplicate indexes. Receive a set indicator for indicating one of a plurality of sets, where each set includes a plurality of subframe values. The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set. 13. The communication apparatus claimed in claim 12, wherein the communication circuitry and processing circuitry are configured to receive the downlink transmission on the Physical Downlink Shared Channel (PDSCH), or wherein the downlink transmission is a transport block. 14. The communication apparatus claimed in claim 12 or 13, wherein the subframe value indicates the number of subframes used to carry the downlink transmission via repetition or bundling. 15. The communication apparatus claimed in any one of claims 12 to 13, wherein the control information is downlink control information (DCI). 16. The communication device claimed in any one of claims 12 to 13, wherein the communication circuitry is configured to transmit and/or receive with reduced radio frequency (RF) bandwidth, or the communication device is a low-cost LC or coverage-enhanced CE communication device. 17. The communication apparatus claimed in any one of claims 12 to 13, wherein the processing circuitry is configured to decode the downlink transmission according to the number of subframes used to carry the downlink transmission. 18. A method in a communication apparatus for transmitting downlink data across multiple subframes, comprising: Transmitting control information including duplicate indexes, Transmit a set indicator for indicating one of multiple sets, where each set includes multiple subframe values, and The number of subframes used to carry the downlink transmission is indicated by the subframe value, and the subframe value is indicated by the repetition index within the indicated set. 19. The method claimed in claim 18, wherein the communication device is a base station. 20. The method claimed in claim 18 or 19, further comprising transmitting the set indicator separately from transmitting the repeating index. 21. The method claimed in any one of claims 18 to 19, wherein the frequency of signaling for transmitting the set indicator is less than the frequency of transmitting the duplicate index. 22. The method claimed in any one of claims 18 to 19, wherein transmitting the set indicator comprises transmitting the set indicator via higher-layer signaling. 23. The method claimed in any one of claims 18 to 19, wherein transmitting the control information includes transmitting a first field and a second field, the first field including an indication of modulation and coding scheme, and the second field including the repeat index. 24. A communication apparatus comprising a communication circuit configured to transmit and receive wireless communications, and a processing circuit communicationally coupled to the communication circuit, wherein the processing circuit is configured to transmit downlink transmissions across a plurality of subframes via the communication circuit and to transmit signaling via the communication circuit, the signaling including: control information including a repetition index; and a set indicator for indicating one of a plurality of sets, wherein each set includes a plurality of subframe values, wherein the number of subframes used to carry the downlink transmissions is indicated by the subframe values, and wherein the subframe values are indicated by the repetition index within the indicated set. 25. The communication device claimed in claim 24, wherein the communication device is a base station. 26. The communication apparatus claimed in claim 24 or 25, wherein the processing circuitry is configured to transmit the set indicator separately from the repeating index. 27. The communication apparatus claimed in any one of claims 24 to 25, wherein the frequency of transmitting signaling including the set indicator is less than the frequency of transmitting signaling including the repeat index. 28. The communication apparatus claimed in any one of claims 24 to 25, wherein the processing circuitry is configured to transmit the set indicator via higher-layer signaling. 29. The communication apparatus claimed in any one of claims 24 to 25, wherein the processing circuitry is configured to transmit the control information, the control information including a first field and a second field, the first field including an indication of modulation and coding scheme, and the second field including the repeat index. 30. A computer-readable storage medium comprising instructions that, when executed by at least one processor of a device, cause the device to perform the method as claimed in any one of claims 1 to 11 or 18 to 23.