Methods and apparatus for multi-carrier communication systems with automatic repeat request (ARQ)
Hybrid ARQ is employed in a multi-carrier communication system for retransmission of erroneous packets by taking advantage of time/frequency/space diversity and by combining ARQ functions at physical layer and MAC layers, making the multi-carrier system more robust in a high packet-error environment.
1. A method for a transmitter with multiple transmission antennas in a wireless communication system, the method comprising:
configuring a first subchannel and a second subchannel in the spatial domain for signal transmissions to a receiver in the communication system, the first and second subchannels containing Orthogonal Frequency Division Multiplexing (OFDM) subcarriers;
transmitting concurrently to the receiver, at a first transmission time a first data packet over the first subchannel and a second data packet over the second subchannel;
receiving a signal from the receiver, the signal indicating an error in the first data packet received by the receiver;
providing, to the receiver, information regarding a retransmission process for a data packet received in error, the information indicating a use of subchannel swapping for retransmission; and
transmitting concurrently to the receiver, at a second transmission time, a redundancy version of the first data packet over the second subchannel and a third packet over the first subchannel, the third packet being swapped from transmission over the second subchannel.
2. The method of claim 1 , wherein the transmission over the first or second subchannel uses an adaptive modulation and coding scheme.
3. The method of claim 2 , wherein the retransmission process uses an adaptive modulation and coding scheme for retransmission of the redundancy version of the first data packet.
4. The method of claim 1 , wherein the transmission over the first or second subchannel uses a rate-matching scheme.
5. The method of claim 1 , wherein the redundancy version of the first data packet is a progressive parity packet of the first data packet.
6. The method of claim 1 , wherein the signal from the receiver indicating an error in the first data packet is a negative acknowledgement (NACK) from the receiver.
7. The method of claim 1 , further comprising receiving a channel quality indicator (CQI) or channel measurements from the receiver.
8. A wireless communication system with multiple transmission antennas, the wireless communication system comprising:
a transmitter to:
allocate a first subchannel and a second subchannel in the spatial domain for signal transmissions to a receiver in the communication system, the first and second subchannels containing Orthogonal Frequency Division Multiplexing (OFDM) subcarriers;
transmit concurrently to the receiver, at a first transmission time, a first data packet over the first subchannel and a second data packet over the second subchannel; and
receive a signal from the receiver, the signal indicating an error in the first data packet received by the receiver; and
a scheduler to provide to the receiver information regarding a retransmission process for a data packet received in error, the control information indicating a use of subchannel swapping for retransmission;
wherein the transmitter is further configured to transmit concurrently to the receiver, at a second transmission time, a redundancy version of the first data packet over the second subchannel and a third packet over the first subchannel, the third packet being swapped from transmission over the second subchannel.
9. The system of claim 8 , wherein the transmitter is further configured to receive a channel quality indicator (CQI) or channel measurements from the receiver.
10. A method for a receiver in a wireless communication system, the method comprising:
concurrently receiving from a transmitter, at a first reception time, a first data packet over a first subchannel and a second data packet over a second subchannel, wherein the first and second subchannels have different spatial configurations;
transmitting a signal to the transmitter, the signal indicating an error in the first data packet received by the receiver;
receiving information regarding a retransmission process for a data packet received in error, the information indicating a use of subchannel swapping for retransmission by the transmitter; and
concurrently receiving, at a second reception time, a redundancy version of the first data packet over the second subchannel and a third packet over the first subchannel, the third packet being swapped from transmission over the second subchannel.
11. The method of claim 10 , wherein the reception over the first or second subchannel uses an adaptive modulation and coding scheme.
12. The method of claim 11 , wherein the retransmission process uses an adaptive modulation and coding scheme for retransmission of the redundancy version of the first data packet.
13. The method of claim 10 , wherein the reception over the first or second subchannel uses a rate-matching scheme.
14. The method of claim 10 , wherein the redundancy version of the first data packet is a progressive parity packet of the first data packet.
15. The method of claim 10 , wherein the transmitted signal to the transmitter is a negative acknowledgement (NACK).
16. The method of claim 10 , further comprising transmitting a channel quality indicator (CQI) or channel measurements to the transmitter.
17. A wireless communication system, the wireless communication system comprising:
a receiver to concurrently receive from a transmitter, at a first reception time, a first data packet over a first subchannel and a second data packet over a second subchannel, wherein the first and second subchannels have different spatial configurations; and
an acknowledgement transmitter configured to transmit a signal to the transmitter, the signal indicating an error in the first data packet received by the receiver;
wherein the receiver is further configured to:
receive information regarding a retransmission process for a data packet received in error, the information indicating a use of subchannel swapping for retransmission by the transmitter; and
concurrently receive, at a second reception time, a redundancy version of the first data packet over the second subchannel and a third packet over the first subchannel, the third packet being swapped from transmission over the second subchannel.
18. The system of claim 17 , wherein the acknowledgement transmitter is further configured to transmit a channel quality indicator (CQI) or channel measurements to the transmitter.