Patent Description:
<CIT> discloses techniques for a multi-user data packet, such as a physical downlink shared channel (PDSCH) packet. It discloses a method for wireless communication by a base station (BS). The method generally includes sending a physical downlink control channel (PDCCH) scheduling a plurality of user equipment (UEs) for a PDSCH transmission. The BS sends data for the plurality of UEs in a single transport block on the scheduled PDSCH.

In accordance with the present invention, there is provided a method for wireless communication performed by a base station as set out in claim <NUM>, a method for wireless communication performed by a UE as set out in claim <NUM>, a base station for wireless communication as set out in claim <NUM>, and a UE for wireless communication as set out in claim <NUM>. Other aspects of the invention can be found in the dependent claims Any embodiment referred to and not falling within the scope of the claims is merely an example useful to the understanding of the invention.

It should be noted that while aspects may be described herein using terminology commonly associated with a <NUM> or NR radio access technologies (RAT), aspects of the present disclosure can be applied to other RATs, such as a <NUM> RAT, a <NUM> RAT, and/or a RAT subsequent to <NUM> (e.g., <NUM>).

Transmit processor <NUM> may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS), a demodulation reference signal (DMRS), and/or the like) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS)).

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with soft-combining for hybrid automatic repeat request feedback, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. In some aspects, memory <NUM> and/or memory <NUM> may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station <NUM> and/or the UE <NUM>, may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like.

In some aspects, UE <NUM> may include means for receiving a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block, means for transmitting hybrid automatic repeat request (HARQ) feedback indicating a decoding failure of a particular transport block of the multi-user packet, means for receiving a retransmission of one or more packets to convey one or more transport blocks, including the particular transport block, subject to one or more respective decoding failures, and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>, such as controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, and/or the like.

In some aspects, base station <NUM> may include means for transmitting, to a group of UEs, a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block, means for receiving, from one or more UEs of the group of UEs, HARQ feedback indicating a decoding failure of one or more transport blocks of the multi-user packet, means for retransmitting one or more packets to convey the one or more transport blocks subject to the decoding failure, and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>, such as antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like.

In some communications systems, UEs and/or BSs may transmit relatively small data packets. For example, in Industrial Internet of Things (IIoT) deployments, BSs may transmit data packets that are much smaller than those transmitted to other types of UEs, such as smart phones. To improve coding gain and increase an efficiency of network resource utilization, a BS may combine a plurality of packets into a single packet and transmit the single packet to a plurality of UEs. The single packet may be termed a multi-user packet. For example, a BS may combine a first packet that is to be transmitted to a first UE with a second packet that is to be transmitted to a second UE into a single multi-user packet. In this case, the BS may transmit the single multi-user packet to the first UE and the second UE. The first UE and the second UE may then recover respective packets concatenated within the single multi-user packet.

When generating a multi-user packet, the BS may concatenate a plurality of transport blocks into a single aggregated transport block, thereby consolidating a plurality of packets (e.g., that were to convey the plurality of transport blocks) into a single multi-user packet. The BS may add a physical (PHY) layer header to the aggregated transport block to form a combined transport block. The BS may transmit the combined transport block via a multi-user packet in a physical downlink shared channel (PDSCH).

In connection with transmitting the multi-user packet, the BS may transmit downlink control information (DCI) with a group radio network temporary identifier (G-RNTI) to a group of UEs for which the multi-user packet includes respective transport blocks. In this case, each UE, of the group of UEs, may use the G-RNTI to decode the multi-user packet of the PDSCH and recover a respective transport block. Based at least in part on decoding the multi-user packet and parsing a header thereof, each UE may identify a respective transport block. For example, the multi-user packet may have a first header indicating that a first transport block is for a first UE, a second header indicating that a second transport block is for a second UE, and/or the like.

In some cases, when a UE fails to decode a packet, the UE may request a retransmission. For example, when a UE fails to decode a packet, the UE may transmit a hybrid automatic repeat request (HARQ) feedback message, such as a HARQ NACK, to a BS. The BS may receive the HARQ feedback message and retransmit the packet. However, retransmitting a whole multi-user packet to ensure that a single transport block thereof is successfully decoded may result in an inefficient utilization of network resources.

Some aspects described herein use soft-combining for HARQ messages for multi-user packet deployments. For example, a BS may encode and transmit a multi-user packet and may receive a HARQ NACK for the multi-user packet, which may trigger a retransmission. In this case, the BS may retransmit only transport blocks for which one or more HARQ NACKs are received (and not transport blocks for which a HARQ acknowledgement (ACK) is received). In some aspects, the BS may generate a new multi-user packet to convey the transport blocks for which the HARQ NACK is received, thereby improving an efficiency of network resource utilization relative to transmitting dedicated packets for each transport block. Additionally, or alternatively, the BS may fill the multi-user packet with new transport blocks (along with retransmitted transport blocks), thereby further improving an efficiency of network resource utilization.

<FIG> are diagrams illustrating examples <NUM>/<NUM>/<NUM>/<NUM> of soft-combining for HARQ feedback, in accordance with various aspects of the present disclosure. As shown in <FIG>, examples <NUM>/<NUM>/<NUM>/<NUM> may include a BS <NUM> and a group of UEs <NUM>.

As further shown in <FIG>, and by reference number <NUM>, BS <NUM> may generate a transport block for a multi-user packet. For example, at <NUM>, BS <NUM> may identify a set of transport blocks for aggregation and a set of headers corresponding to the set of transport blocks. In this case, the set of transport blocks may include a first transport block conveying data for a first UE <NUM> and associated with a first sub-header, a second transport block conveying data for a second UE <NUM> and associated with a second sub-header, a third transport block conveying data for a third UE <NUM> and associated with a first sub-header, and/or the like. At <NUM>, BS <NUM> may apply a common coding scheme to each of the set of transport blocks. For example, BS <NUM> may perform cyclic redundancy check (CRC) insertion and code block segmentation to each transport block to generate low-density parity check (LDPC) coded code blocks. At <NUM>, BS <NUM> may apply rate matching and coded bit selection to each LDPC coded code block to generate a set of coded transport blocks for each UE <NUM> of the group of UEs <NUM>. At <NUM>, BS <NUM> may aggregate the coded transport blocks into a single combined coded transport block (which may be termed a transport block set) and may apply polar coding to the sub-headers to generate a single polar coded code block (which may be termed a sub-header set). In this case, as shown by reference number <NUM>, BS <NUM> may transmit a PDSCH that includes a first multi-user packet to convey the sub-header set and the transport block set.

As shown in <FIG>, and in example <NUM>, the first multi-user packet may include a header and a set of aggregated transport blocks with respective CRCs, and BS <NUM> may transmit the first multi-user packet with a DCI (e.g., including a multi-user (MU)-RNTI). As shown by reference number <NUM>, transport blocks TB1 and TB2 are decoded successfully (e.g., BS <NUM> receives HARQ ACKs for TB1 and TB2), but transport blocks TB0 and TB3 are not decoded successfully (e.g., BS <NUM> receives HARQ NACKs for TB0 and TB3 from respective UEs <NUM>).

In this case, as shown by reference number <NUM>, BS <NUM> may retransmit unsuccessfully decoded transport blocks. For example, BS <NUM> may transmit a second multi-user packet including a header and the unsuccessfully decoded transport blocks with respective CRCs, but not with the successfully decoded transport blocks. In this way, BS <NUM> reduces a utilization of network resources. A UE <NUM> may perform soft-combining for TB0 from the first multi-user packet (e.g., TB0 redundancy version (rv) <NUM> (rv0) with TB0 from the second multi-user packet (TB0 rv1), which may improve a likelihood that the UE <NUM> successfully decodes TB0.

As further shown in <FIG>, and by reference number <NUM>, based at least in part on TB0 being successfully decoded using soft-combining (e.g., UE <NUM> may use a circular buffer to perform soft-combining and may provide a HARQ ACK to BS <NUM>) and TB3 not being successfully decoded despite using soft-combining (e.g., when BS <NUM> receives a HARQ NACK), BS <NUM> may determine to re-transmit TB3. In this case, based at least in part on there being a single transport block to transmit, rather than a plurality of transport blocks, BS <NUM> may transmit a dedicated (e.g., non-multi-user) packet with an MU-RNTI or a T-RNTI in a corresponding DCI. In this case, UE <NUM> may use soft-combining for TB3s from the first multi-user packet (e.g., TB3 rv0), the second multi-user packet (e.g., TB3 rv1), and the dedicated packet (e.g., TB3 rv2). In this case, a UE <NUM> is successful at decoding TB3.

As shown in <FIG>, and by example <NUM> and reference number <NUM>, in another example, when respective UEs <NUM> do not successfully decode TB0 and TB3 based at least in part on a transmission of the first multi-user packet, BS <NUM> may generate a second multi-user packet that includes TB0, TB3, and one or more new transport blocks. For example, BS <NUM> may include new transport blocks TB4 and TB5 in the second multi-user packet. In this way, BS <NUM> ensures efficient utilization of network resources. Similarly, as shown by reference number <NUM>, when respective UEs <NUM> do not successfully decode TB3 (e.g., based at least in part on soft-combining TB3 rv0 and TB3 rv1) and TB5, BS <NUM> may generate a third multi-user packet that includes TB3, TB5, and one or more new transport blocks (e.g., TB6 and TB7). In some aspects, BS <NUM> may include a single DCI for a multi-user packet that includes a retransmission and a new packet. For example, BS <NUM> may include HARQ process identifier information, modulation and coding scheme information, and/or the like, and may include a new sub-header to enable UEs <NUM> that receive the DCI to determine a size and set of resources within the PDSCH. In some aspects, sub-headers of the multi-user packet may include transport block size and/or other information to enable UEs <NUM> to determine which transport blocks are for which UEs <NUM>. For example, BS <NUM> may include a new data indicator (NDI) in each sub-header to enable one or more UEs <NUM> to identify new packets in a retransmission multi-user packet. Additionally, or alternatively, BS <NUM> may include redundancy version information, and/or the like.

As shown in <FIG>, and by example <NUM> and reference number <NUM>, rather than including a plurality of new transport blocks in the second multi-user packet (each with the same size), BS <NUM> may include different sized transport blocks in the second multi-user packet. For example, BS <NUM> may retransmit TB0 and TB3 with the same size in the second multi-user packet as in the first multi-user packet, but may include a new transport block TB4 that is a different size than TB0 and TB3. As shown by reference number <NUM>, when BS <NUM> generates a third multi-user packet to retransmit TB3 and TB4 (e.g., based at least in part on unsuccessful decoding of TB3 and TB4 by respective UEs <NUM>), TB3 and TB4 are each associated with the same respective size as in previous multi-user packets. In other words, TB3 rv0, TB3 rv1, and TB3 rv2 are each associated with a first size and TB4 rv0 and TB4 rv1 are each associated with a second size.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the BS (e.g., BS <NUM> and/or the like) performs operations associated with soft-combining for hybrid automatic repeat request feedback.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a group of UEs, a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block (block <NUM>). For example, the BS (e.g., using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit, to a group of UEs, a multi-user packet including a plurality of transport blocks combined into a combined transport block, as described above. In some aspects, each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block.

As further shown in <FIG>, in some aspects, process <NUM> may include receiving, from one or more UEs of the group of UEs, HARQ feedback indicating a decoding failure of one or more transport blocks of the multi-user packet (block <NUM>). For example, the BS (e.g., using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive, from one or more UEs of the group of UEs, HARQ feedback indicating a decoding failure of one or more transport blocks of the multi-user packet, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include retransmitting one or more packets to convey the one or more transport blocks subject to the decoding failure (block <NUM>). For example, the BS (e.g., using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may retransmit one or more packets to convey the one or more transport blocks subject to the decoding failure, as described above.

In a first aspect, downlink control information, of a physical downlink control channel, associated with the multi-user packet includes information identifying one or more parameters of a physical downlink shared channel with which the multi-user packet is conveyed.

In a second aspect, alone or in combination with the first aspect, downlink control information, of a physical downlink control channel, associated with the multi-user packet includes information identifying one or more parameters of a sub-header set associated with the multi-user packet.

In a third aspect, alone or in combination with one or more of the first and second aspects, one or more sub-headers, of the sub-header set, are jointly encoded using polar encoding.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the plurality of transport blocks are encoded using low-density parity check codes for the group of UEs.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, retransmitting the one or more packets includes retransmitting the one or more packets and refraining from including new transport blocks in a retransmission that includes the one or more packets.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the one or more packets include a single packet, and retransmitting the one or more packets comprises retransmitting the single packet via a unicast transmission.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, downlink control information transmitted in connection with the multi-user packet includes information for at least one of: a frequency domain resource assignment, a time domain resource assignment, a hybrid automatic repeat request process identifier, a modulation and coding scheme, a new data indicator, a redundancy version, a downlink assignment index, or a combination thereof.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, downlink control information transmitted in connection with the multi-user packet includes information identifying a size or set of resources for a sub-header set.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, a first transport block size of the plurality of transport blocks of the multi-user packet and a second transport block size of the one or more transport blocks subject to the decoding failure and included in the one or more packets are a common transport block size.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, retransmitting the one or more packets comprises retransmitting the one or more packets with the one or more transport blocks subject to the decoding failure and with one or more new transport blocks for one or more UEs of the group of UEs in a retransmission.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the retransmission includes a new data indicator to enable the one or more UEs to identify the one or more new transport blocks.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM> and/or the like) performs operations associated with soft-combining for hybrid automatic repeat request feedback.

As shown in <FIG>, in some aspects, process <NUM> may include receiving a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive a multi-user packet including a plurality of transport blocks combined into a combined transport block, as described above. In some aspects, each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting HARQ feedback indicating a decoding failure of a particular transport block of the multi-user packet (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit HARQ feedback indicating a decoding failure of a particular transport block of the multi-user packet, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include receiving a retransmission of one or more packets to convey one or more transport blocks, including the particular transport block, subject to one or more respective decoding failures (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive a retransmission of one or more packets to convey one or more transport blocks, including the particular transport block, subject to one or more respective decoding failures, as described above.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the plurality of transport blocks is encoded using low-density parity check codes for the group of UEs.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, receiving the one or more packets includes receiving the one or more packets and refraining from including new transport blocks in a retransmission that includes the one or more packets.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the one or more packets include a single packet, and receiving the one or more packets includes receiving the single packet via a unicast transmission.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, downlink control information received in connection with the multi-user packet includes information for at least one of: a frequency domain resource assignment, a time domain resource assignment, a hybrid automatic repeat request process identifier, a modulation and coding scheme, a new data indicator, a redundancy version, a downlink assignment index, or a combination thereof.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, downlink control information received in connection with the multi-user packet includes information identifying a size or set of resources for a sub-header set.

Claim 1:
A method of wireless communication performed by a base station, BS, comprising:
transmitting (<NUM>), to a group of user equipment, UEs, a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block;
receiving (<NUM>), from one or more UEs of the group of UEs, hybrid automatic repeat request, HARQ, feedback indicating a decoding failure of one or more transport blocks of the multi-user packet; and
retransmitting (<NUM>) one or more packets to convey the one or more transport blocks subject to the decoding failure.