Transmission of feedback information for multi-carrier operation
Techniques for sending feedback information for multi-carrier operation are described. In an aspect, feedback information may be sent on an uplink carrier that may or may not be paired with a downlink carrier on which data transmission is sent. A user equipment (UE) may receive data transmission on a downlink carrier among a plurality of downlink carriers. The UE may determine feedback information for the data transmission, determine an uplink carrier to use to send the feedback information from among a plurality of uplink carriers, and send the feedback information on the uplink carrier. In another aspect, feedback information for multiple downlink carriers may be sent on at least one uplink carrier using Single-Carrier Frequency Division Multiple Access (SC-FDMA). A UE may receive data transmissions on a plurality of downlink carriers, determine feedback information for the data transmissions, and send the feedback information on at least one uplink carrier using SC-FDMA.
1. A method for wireless communication, comprising:
receiving Radio Resource Control (RRC) signaling identifying a designated uplink carrier;
receiving a data transmission on a first downlink carrier among a plurality of downlink carriers;
determining feedback information for the data transmission;
receiving a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant;
determining to use the designated uplink carrier or the paired uplink carrier to send the feedback information from among a plurality of uplink carriers based on the received flag; and
sending the feedback information on the determined uplink carrier.
2. The method of claim 1 , wherein the feedback information comprises acknowledgement (ACK) information, or channel quality indicator (CQI) information, or both.
3. The method of claim 1 , further comprising:
receiving a downlink grant on a second downlink carrier among the plurality of downlink carriers, wherein the downlink grant is for a data transmission on the second downlink carrier, and wherein the determined uplink carrier to use to send the feedback information is paired with the second downlink carrier used to send the downlink grant.
4. The method of claim 1 , wherein the determined uplink carrier is used to send feedback information for the plurality of downlink carriers.
5. The method of claim 1 , further comprising:
receiving a second data transmission on a second downlink carrier among the plurality of downlink carriers; and
sending feedback information for the second data transmission on the determined uplink carrier.
6. An apparatus for wireless communication, comprising:
means for receiving Radio Resource Control (RRC) signaling indentifying a designated uplink carrier;
means for receiving a data transmission on a first downlink carrier among a plurality of downlink carriers;
means for determining feedback information for the data transmission;
means for receiving a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant;
means for determining to use the designated uplink carrier or the paired uplink carrier to send the feedback information from among a plurality of uplink carriers based on the received flag; and
means for sending the feedback information on the determined uplink carrier.
7. The apparatus of claim 6 , further comprising:
means for receiving a downlink grant on a second downlink carrier among the plurality of downlink carriers, wherein the downlink grant is for a data transmission on the second downlink carrier, and wherein the determined uplink carrier to use to send the feedback information is paired with the second downlink carrier used to send the downlink grant.
8. An apparatus for wireless communication, comprising:
at least one processor configured to receive Radio Resource Control (RRC) signaling identifying a designated uplink carrier, receive a data transmission on a first downlink carrier among a plurality of downlink carriers, to determine feedback information for the data transmission, to receive a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant, to determine to use the designated uplink carrier or the paired uplink carrier to send the feedback information from among a plurality of uplink carriers based on the received flag, and to send the feedback information on the determined uplink carrier.
9. The apparatus of claim 8 , wherein the at least one processor is configured to receive a downlink grant on a second downlink carrier among the plurality of downlink carriers, wherein the downlink grant is for a data transmission on the second downlink carrier, and wherein the determined uplink carrier to use to send the feedback information is paired with the second downlink carrier used to send the downlink grant.
10. A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one computer to receive Radio Resource Control (RRC) signaling indentifying a designated uplink carrier;
code for causing at least one computer to receive a data transmission on a first downlink carrier among a plurality of downlink carriers,
code for causing the at least one computer to determine feedback information for the data transmission,
code for causing the at least one computer to receive a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant;
code for causing the at least one computer to determine to use the designated uplink carrier or the paired uplink carrier to send the feedback information from among a plurality of uplink carriers based on the received flag, and
code for causing the at least one computer to send the feedback information on the determined uplink carrier.
11. A method for wireless communication, comprising:
sending Radio Resource Control (RRC) signaling identifying a designated uplink carrier;
sending a data transmission on a first downlink carrier among a plurality of downlink carriers to a user equipment (UE);
sending a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant,
determining the designated uplink carrier or the paired uplink carrier used by the UE to send feedback information for the data transmission from among a plurality of uplink carriers based on the flag; and
receiving the feedback information on the determined uplink carrier from the UE.
12. The method of claim 11 , further comprising:
sending a downlink grant on a second downlink carrier among the plurality of downlink carriers, wherein the downlink grant is for a data transmission on the second downlink carrier, and wherein the determined uplink carrier used to send the feedback information is paired with the second downlink carrier used to send the downlink grant.
13. The method of claim 11 , further comprising:
sending a second data transmission on a second downlink carrier among the plurality of downlink carriers to the UE; and
receiving feedback information for the second data transmission on the determined uplink carrier from the UE.
14. An apparatus for wireless communication, comprising:
means for sending Radio Resource Control (RRC) signaling identifying a designated uplink carrier;
means for sending a data transmission on a first downlink carrier among a plurality of downlink carriers to a user equipment (UE);
means for sending a flag indicative of whether to use the designated uplink carrier or a paired uplink carrier to send the feedback information, wherein the paired uplink carrier is associated with the first downlink carrier used for the data transmission or another downlink carrier used to send a downlink grant;
means for determining the designated uplink carrier or the paired uplink carrier used by the UE to send feedback information for the data transmission from among a plurality of uplink carriers based on the flag; and
means for receiving the feedback information on the determined uplink carrier from the UE.
15. The apparatus of claim 14 , further comprising:
means for sending a downlink grant on a second downlink carrier among the plurality of downlink carriers, wherein the downlink grant is for a data transmission on the second downlink carrier, and wherein the determined uplink carrier used to send the feedback information is paired with the second downlink carrier used to send the downlink grant.