Methods and apparatus for multi-carrier communications 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 multi-cell 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 signal from the receiver, the signal indicating an error in the data packet received by 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 from a group of subchannels reserved for data retransmission with a higher frequency reuse factor than the first subchannel.
2. The method of claim 1 , wherein the higher frequency reuse factor is chosen to reduce inter-cell interference.
3. The method of claim 1 , wherein the second subchannel is selected randomly from the group of subchannels reserved for data retransmission.
4. The method of claim 1 , wherein the second subchannel is selected based on channel quality of the group of subchannels reserved for data retransmission.
5. The method of claim 1 , wherein the redundancy version of the data packet is a progressive parity packet of the first data packet.
6. The method of claim 1 , further comprising receiving a channel quality indicator (CQI) or channel measurements from the receiver.
7. A multi-cell wireless communication system with multiple transmission antennas, the 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 signal from the receiver, the signal indicating an error in the data packet received by 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 transmit 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 from a group of subchannels reserved for data retransmission with a higher frequency reuse factor than the first subchannel.
8. The system of claim 7 , wherein the higher frequency reuse factor is chosen to reduce inter-cell interference.
9. A method for a transceiver in a multi-cell 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 signal to the transmitter, the signal indicating an error in the data packet received by the transceiver; 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 from a group of subchannels reserved for data retransmission with a higher frequency reuse factor than the first subchannel.
10. The method of claim 9 , wherein the higher frequency reuse factor is employed to reduce inter-cell interference.
11. The method of claim 9 , wherein the second subchannel was selected randomly from the group of subchannels reserved for data retransmission.
12. The method of claim 9 , wherein the second subchannel was selected based on channel quality of the group of subchannels reserved for data retransmission.
13. The method of claim 9 , wherein the transmitted signal to the transmitter is a negative acknowledgement (NACK).
14. The method of claim 9 , further comprising transmitting a channel quality indicator (CQI) or channel measurements to the transmitter.
15. A multi-cell 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 signal to the transmitter, the signal indicating an error in the data packet received by the transceiver; 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 from a group of subchannels reserved for data retransmission with a higher frequency reuse factor than the first subchannel.
16. The system of claim 15 , wherein the transceiver is further configured to transmit a channel quality indicator (CQI) or channel measurements to the transmitter.