Method and system for supporting multiple hybrid automatic repeat request processes per transmission time interval
A method and apparatus may be used for supporting multiple hybrid automatic repeat request (H-ARQ) processes per transmission time interval (TTI). A transmitter and a receiver may include a plurality of H-ARQ processes. Each H-ARQ process may transmit and receive one TB per TTI. The transmitter may generate a plurality of TBs and assign each TB to a H-ARQ process. The transmitter may send control information for each TB, which may include H-ARQ information associated TBs with the TBs. The transmitter may send the TBs using the associated H-ARQ processes simultaneously per TTI. After receiving the TBs, the receiver may send feedback for each of the H-ARQ processes and associated TBs indicating successful or unsuccessful receipt of each of the TBs to the transmitter. The feedback for multiple TBs may be combined for the simultaneously transmitted H-ARQ processes, (i.e., TBs). When MIMO is implemented, one H-ARQ process may be associated with one MIMO stream, or codeword. The feedback may include a channel quality indicator (CQI) per MIMO stream or codeword. The control information and the feedback may be sent via a layer 1 or layer 2/3 control part.
1. A wireless transmit/receive unit (WTRU) comprising:
a receiver configured to receive a single control message including control information for a plurality of transport blocks; wherein for each transport block, the control information includes a modulation and coding scheme (MCS) and a redundancy version for that transport block; wherein the receiver is further configured using the control information, to receive the plurality of transport blocks in a single transmission time interval (TTI); and
a transmitter configured to transmit indications of an acknowledgment (ACK) or negative acknowledgment (NACK) for each of the plurality of transport blocks; wherein the indications of an ACK or NACK for each of the transport blocks are transmitted in a single packet.
2. The WTRU of claim 1 , wherein a modulation and coding scheme for the single packet is based on a number of indications of an ACK or NACK for each of the transport blocks.
3. The WTRU of claim 1 , wherein a number of antennas used for transmission of the single packet is based on a number of indications of an ACK or NACK.
4. The WTRU of claim 1 , wherein the indications of an ACK or NACK for each of the transport blocks are transmitted in a control portion of physical uplink subframe.
5. The WTRU of claim 1 wherein control information for a first transport block including the MCS and redundancy version for the first transport block is concatenated with control information for a second transport block including the MCS and redundancy version for the second transport block.
6. The WTRU of claim 1 wherein the single control message includes a HARQ process ID associated with at least one of the transport blocks.
7. The WTRU of claim 1 wherein the single control message includes an indication of to which subcarriers the transport blocks are mapped.
8. A method comprising:
receiving, by a wireless transmit/receive unit (WTRU), a single control message including control information for a plurality of transport blocks; wherein for each transport block, the control information includes a modulation and coding scheme (MCS) and a redundancy version for that transport block;
using the control information to receive the plurality of transport blocks in a single transmission time interval (TTI); and
transmitting indications of an acknowledgment (ACK) or negative acknowledgment (NACK) for each of the plurality of transport blocks; wherein the indications of an ACK or NACK for each of the transport blocks are transmitted in a single packet.
9. The method of claim 8 , wherein a modulation and coding scheme for the single packet is based on a number of indications of an ACK or NACK.
10. The method of claim 8 , wherein a number of antennas used for transmission of the single packet is based on a number of indications of an ACK or NACK.
11. The method of claim 8 , wherein the indications of an ACK or NACK for each of the transport blocks are transmitted in a control portion of physical uplink subframe.
12. The method of claim 8 wherein control information for a first transport block including the MCS and redundancy version for the first transport block is concatenated with control information for a second transport block including the MCS and redundancy version for the second transport block.
13. The method of claim 8 wherein the single control message includes a HARQ process ID associated with at least one of the transport blocks.
14. The method of claim 8 wherein the single control message includes an indication of to which subcarriers the transport blocks are mapped.