Channel state information transmission for multiple carriers
Channel state information is reported in periodic and aperiodic reports for multiple component carriers or serving cells. Channel state information may be reported for a subset of aggregated downlink carriers or serving cells. For an aperiodic report, the carrier(s)/serving cell(s) for which channel state information is reported are determined based on the request for the aperiodic report. When a CQI/PMI/RI report and a HARQ ACK/NACK report coincide in a subframe, the HARQ ACK/NACK report is transmitted on PUCCH, and the CQI/PMI/RI report is transmitted on PUSCH.
1. A method for reporting channel state information (CSI), the method comprising:
receiving an indication to send an aperiodic CSI report;
determining a CSI request field from the indication, the CSI request field indicating how a wireless transmit/receive unit (WTRU) should determine a serving cell;
determining the serving cell for reporting CSI using the CSI request field, the serving cell being part of a plurality of aggregated serving cells; and
sending the aperiodic CSI report for the determined serving cell.
2. The method of claim 1 , wherein the indication comprises a downlink control information (DCI) format.
3. The method of claim 1 , wherein the serving cell is an uplink serving cell on which the aperiodic CSI report can be sent using a physical uplink shared channel (PUSCH).
4. The method of claim 1 , wherein sending the aperiodic CSI report for the determined serving cell comprises:
determining a set of subframes for the serving cell; and
sending the aperiodic CSI report for the serving cell when a subframe belongs to the set of subframes.
5. The method of claim 1 , wherein sending the aperiodic CSI report for the determined serving cell comprises:
determining a first set of subframes for a first serving cell;
determining a second set of subframes for a second serving cell, the first serving cell and the second serving cell being part of a plurality of aggregated serving cells; and
sending the aperiodic CSI for the second serving cell when a subframe belongs to the second set of subframes.
6. The method of claim 1 , wherein the indication comprises a downlink control information (DCI) format and the CSI request field comprises a bit map.
7. The method of claim 1 , wherein determining the serving cell for reporting CSI using the CSI request field comprises:
determining that the CSI request field indicates that the aperiodic CSI report is triggered for a set of serving cells configured by a higher layer; and
determining the serving cell from the set of serving cells.
8. The method of claim 7 , further comprising determining the set of serving cells configured by the higher layer using the CSI request field.
9. The method of claim 7 , further comprising determining that the CSI request field has 2 bits.
10. A wireless transmit and receive unit (WTRU) for reporting channel state information (CSI), the WTRU comprising:
a processor configured to:
receive an indication to send an aperiodic CSI report;
determine a CSI request field from the indication, the CSI request field indicating how the WTRU should determine a serving cell;
determine the serving cell for reporting CSI using the CSI request field, the serving cell being part of a plurality of aggregated serving cells; and
send the aperiodic CSI report for the determined serving cell.
11. The WTRU of claim 10 , wherein the indication to transmit the aperiodic CSI report comprises a downlink control information (DCI) format.
12. The WTRU of claim 11 , wherein the serving cell is an uplink serving cell on which the aperiodic CSI report can be sent using a physical uplink shared channel (PUSCH).
13. The WTRU of claim 10 , wherein the processor is further configured to send the aperiodic CSI report for the determined serving cell by:
determining a set of subframes for the serving cell; and
sending the aperiodic CSI report for the serving cell when a subframe belongs to the set of subframes.
14. The WTRU of claim 10 , wherein the indication comprises a downlink control information (DCI) format and the CSI request field comprises a bit map.
15. The WTRU of claim 10 , wherein the processor is configured to determine the serving cell for reporting CSI using the CSI request field by:
determining the CSI request field indicates that the aperiodic CSI report is triggered for a set of serving cells configured by a higher layer; and
determining the serving cell from the set of serving cells.
16. The WTRU of claim 15 , wherein the processor is further configured to determine the set of serving cells configured by the higher layer using the CSI request field.
17. The WTRU of claim 15 , further comprising determining that the CSI request field has 2 bits.