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 transceiver in a wireless communication system, the method comprising:
transmitting a data packet over a first subchannel to a receiver at a first transmission time, the first subchannel containing a first group of subcarriers;
receiving a channel quality indicator (CQI) from the receiver; and
transmitting, at a second transmission time different from the first transmission time, a redundancy version of the data packet to the receiver over a second subchannel and transmitting another data packet originally scheduled for the second subchannel over the first subchannel, the second subchannel containing a second group of subcarriers, wherein the second subchannel is selected based on the CQI.
2. The method of claim 1 , further comprising receiving a signal from the receiver, the signal indicating an error in the data packet received by the receiver.
3. The method of claim 2 , wherein the CQI is received with the signal from the receiver at substantially the same time.
4. The method of claim 1 , wherein the transmission over the first or second subchannel uses an adaptive modulation and coding scheme.
5. The method of claim 1 , wherein the transmission over the second subchannel uses a same modulation scheme as the transmission over the first subchannel.
6. The method of claim 1 , wherein the redundancy version of the data packet is a progressive parity packet of the first data packet.
7. A wireless communication system comprising a transceiver configured to:
transmit a data packet over a first subchannel to a receiver at a first transmission time, the first subchannel containing a first group of subcarriers;
receive a channel quality indicator (CQI) from the receiver; and
transmit, at a second transmission time different from the first transmission time, a redundancy version of the data packet to the receiver over a second subchannel and transmitting another data packet originally scheduled for the second subchannel over the first subchannel, the second subchannel containing a second group of subcarriers, wherein the second subchannel is selected based on the CQI.
8. The system of claim 7 , wherein the transceiver is further configured to receive a signal from the receiver, the signal indicating an error in the data packet received by the receiver.
9. A method for a transceiver in a wireless communication system, the method comprising:
receiving a data packet over a first subchannel from a transmitter at a first transmission time, the first subchannel containing a first group of subcarriers;
transmitting a channel quality indicator (CQI) to the transmitter; and
receiving, at a second transmission time different from the first transmission time, a redundancy version of the data packet from the transmitter over a second subchannel and receiving another data packet originally scheduled for the second subchannel over the first subchannel, the second subchannel containing a second group of subcarriers, wherein the second subchannel was selected based on the CQI.
10. The method of claim 9 , further comprising transmitting a signal to the transmitter, the signal indicating an error in the data packet received by the transceiver.
11. The method of claim 10 , wherein the CQI is transmitted with the signal to the transmitter at substantially the same time.
12. The method of claim 9 , wherein the reception over the first or second subchannel uses an adaptive modulation and coding scheme.
13. The method of claim 9 , wherein the reception over the second subchannel is based on a same modulation scheme as the reception over the first subchannel.
14. The method of claim 9 , wherein the redundancy version of the data packet is a progressive parity packet of the first data packet.
15. A wireless communication system, the wireless communication system comprising a transceiver configured to:
receive a data packet over a first subchannel from a transmitter at a first transmission time, the first subchannel containing a first group of subcarriers;
transmit a channel quality indicator (CQI) to the transmitter; and
receive, at a second transmission time different from the first transmission time, a redundancy version of the data packet from the transmitter over a second subchannel and receive another data packet originally scheduled for the second subchannel over the first subchannel, the second subchannel containing a second group of subcarriers, wherein the second subchannel was selected based on the CQI.
16. The system of claim 15 , wherein the transceiver is further configured to transmit a signal to the transmitter, the signal indicating an error in the data packet received by the transceiver.
17. The system of claim 16 , wherein the CQI is transmitted with the signal to the transmitter at substantially the same time.
18. The system of claim 15 , wherein the reception over the first or second subchannel uses an adaptive modulation and coding scheme.
19. The system of claim 15 , wherein the redundancy version of the data packet is a progressive parity packet of the first data packet.