Method and apparatus for reporting feedback information for multi-carrier operation

1. A wireless transmit/receive unit (WTRU) comprising:

a transceiver; and

a processor operatively coupled to the transceiver; wherein:

the transceiver is configured to receive a first control message including both information indicating a first allocation of resources for a first downlink transmission on a first downlink carrier and a first indication of resources for feedback corresponding to the first downlink transmission, wherein the first indication of resources for feedback includes an indication of at least one orthogonal frequency division multiplex (OFDM) symbol and an indication of at least one subcarrier;

the transceiver is configured to receive the first downlink transmission in the first allocation of resources on the first downlink carrier;

the processor is configured to derive acknowledgement/negative acknowledgement (ACK/NACK) feedback corresponding to the first downlink transmission; and

the transceiver and the processor are configured to transmit the derived ACK/NACK feedback in the at least one OFDM symbol and on the at least one subcarrier, based on the first indication of resources for feedback.

2. The WTRU of claim 1 , wherein the transceiver is further configured to receive a second control message including information indicating a second allocation of resources for a second downlink transmission on a second downlink carrier, wherein the first downlink transmission and the second downlink transmission would at least partially overlap in time.

3. The WTRU of claim 2 , wherein the second control message further includes a second indication of resources for feedback corresponding to the second downlink transmission.

4. The WTRU of claim 1 , wherein an indication of a carrier of the feedback is not included with the ACK/NACK feedback.

5. The WTRU of claim 1 , wherein the first indication of resources for feedback is an index.

6. The WTRU of claim 1 , wherein the transceiver is further configured to receive information indicating an allocation of a plurality of resources for feedback channels.

7. A method in a wireless transmit/receive unit (WTRU), the method comprising:

receiving a first control message including both information indicating a first allocation of resources for a first downlink transmission on a first downlink carrier and a first indication of resources for feedback corresponding to the first downlink transmission, wherein the first indication of resources for feedback includes an indication of at least one orthogonal frequency division multiplex (OFDM) symbol and an indication of at least one subcarrier;

receiving the first downlink transmission in the first allocation of resources on the first downlink carrier;

deriving acknowledgement/negative acknowledgement (ACK/NACK) feedback corresponding to the first downlink transmission; and

transmitting the derived ACK/NACK feedback in the at least one OFDM symbol and on the at least one subcarrier, based on the first indication of resources for feedback.

8. The method of claim 7 , further comprising:

receiving a second control message including information indicating a second allocation of resources for a second downlink transmission on a second downlink carrier, wherein the first downlink transmission and the second downlink transmission would at least partially overlap in time.

9. The method of claim 8 , wherein the second control message further includes a second indication of resources for feedback corresponding to the second downlink transmission.

10. The method of claim 7 , wherein an indication of a carrier of the feedback is not included with the ACK/NACK feedback.

11. The method of claim 7 , wherein the first indication of resources for feedback is an index.

12. The method of claim 7 , further comprising:

receiving information indicating an allocation of a plurality of resources for feedback channels.

13. A base station comprising:

a transceiver; and

a processor operatively coupled to the transceiver; wherein:

the transceiver and the processor are configured to transmit a first control message including both information indicating a first allocation of resources for a first downlink transmission on a first downlink carrier and a first indication of resources for feedback corresponding to the first downlink transmission, wherein the first indication of resources for feedback includes an indication of at least one orthogonal frequency division multiplex (OFDM) symbol and an indication of at least one subcarrier;

the transceiver and the processor are configured to transmit the first downlink transmission in the first allocation of resources on the first downlink carrier; and

the transceiver is configured to receive acknowledgement/negative acknowledgement (ACK/NACK) feedback, corresponding to the first downlink transmission, in the at least one OFDM symbol and on the at least one subcarrier, based on the first indication of resources for feedback.

14. The base station of claim 13 , wherein the transceiver and processor are further configured to transmit a second control message including information indicating a second allocation of resources for a second downlink transmission on a second downlink carrier, wherein the first downlink transmission and the second downlink transmission would at least partially overlap in time.

15. The base station of claim 14 , wherein the second control message further includes a second indication of resources for feedback corresponding to the second downlink transmission.

16. The base station of claim 13 , wherein an indication of a carrier of the feedback is not included with the ACK/NACK feedback.

17. The base station of claim 13 , wherein the first indication of resources for feedback is an index.

18. The base station of claim 13 , wherein the transceiver and processor are further configured to transmit information indicating an allocation of a plurality of resources for feedback channels.