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 activate a semi-persistent CSI reporting;
activating the semi-persistent CSI reporting for a serving cell based on the received indication;
transmitting one or more CSI reports for the serving cell, after the semi-persistent CSI reporting is activated;
determining that a time alignment timer (TAT) has expired; and
deactivating the semi-persistent CSI reporting based on expiration of the TAT.
2. The method of claim 1 , wherein the received indication comprises any of: a downlink control information (DCI) format, or a random access response grant.
3. The method of claim 1 , further comprising at least one of:
determining the serving cell of a Physical Downlink Control Channel (PDCCH) on which the received indication is decoded; or
determining the serving cell corresponding to a Physical Downlink Shared Channel (PDSCH) on which the received indication is decoded.
4. The method of claim 1 , further comprising determining a CSI request field from the received indication, wherein the CSI request field indicates the activating or the deactivating of the semi-persistent CSI reporting.
5. The method of claim 1 , wherein the one or more CSI reports are transmitted on a physical uplink shared channel (PUSCH).
6. The method of claim 1 , wherein the one or more CSI reports are transmitted periodically.
7. The method of claim 1 , wherein the received indication activates the semi-persistent CSI reporting based on downlink control information (DCI) scrambled with a Radio Network Temporary Identifier (RNTI).
8. The method of claim 1 , wherein the deactivating of the semi-persistent CSI reporting comprises:
refraining from transmitting the one or more additional CSI reports.
9. A wireless transmit and receive unit (WTRU), comprising:
a transceiver configured to receive an indication to activate a semi-persistent channel state information (CSI) reporting; and
a processor configured to activate the semi-persistent CSI reporting for a serving cell based on the received indication;
wherein:
the transceiver is configured to transmit one or more CSI reports for the serving cell, after the semi-persistent CSI reporting is activated, and
the processor is configured to:
determine that a time alignment timer (TAT) has expired, and
deactivate the semi-persistent CSI reporting based on expiration of the TAT.
10. The WTRU of claim 9 , wherein the received indication comprises any of: a downlink control information (DCI) format, or a random access response grant.
11. The WTRU of claim 9 , wherein the processor is configured to:
determine the serving cell of a Physical Downlink Control Channel (PDCCH) on which the received indication is decoded; or
determine the serving cell corresponding to a Physical Downlink Shared Channel (PDSCH) on which the received indication is decoded.
12. The WTRU of claim 9 , wherein the processor is configured to determine a CSI request field from the received indication, wherein the CSI request field indicates activating or deactivating the semi-persistent CSI reporting.
13. The WTRU of claim 9 , wherein the transceiver is configured to transmit the one or more CSI reports on a physical uplink shared channel (PUSCH).
14. The WTRU of claim 9 , wherein the transceiver is configured to transmit the one or more CSI reports periodically.
15. The WTRU of claim 9 , wherein the received indication activates the semi-persistent CSI reporting based on downlink control information (DCI) scrambled with a Radio Network Temporary Identifier (RNTI).
16. The WTRU of claim 9 , wherein the processor is configured to refrain from transmitting one or more additional CSI reports, when the semi-persistent CSI reporting is deactivated.