Coding and multiplexing of control information in a wireless communication system
Techniques for sending control information in a wireless communication system are described. In an aspect, a UE spreads control information across frequency with a DFT and across time with an orthogonal sequence to obtain output data for the control information. In one design, the UE receives codewords for N HARQ processes in N downlink subframes, determines an ACK value for each HARQ process, codes N ACK values for the N HARQ processes to obtain ACK information, generates output data for the ACK information, and sends the output data in one of M uplink subframes. In another aspect, first control information is processed based on a first coding and multiplexing scheme utilizing code division multiplexing in time and frequency domains. Second control information is processed based on a second coding and multiplexing scheme utilizing code division multiplexing in time domain and spreading in frequency domain.
1. A method of sending data in a wireless communication system utilizing time division duplexing (TDD), comprising:
receiving a sounding reference signal on an uplink;
determining a precoding matrix for data transmission on a downlink, based on the sounding reference signal;
determining at least one modulation and coding scheme for the data transmission on the downlink, based on the sounding reference signal;
sending the data transmission on the downlink based on the precoding matrix and the at least one modulation and coding scheme;
receiving channel quality indicator (CQI) information indicative of channel quality of the downlink;
estimating noise and interference for the uplink based on the sounding reference signal;
determining asymmetry of noise and interference for the downlink and the uplink based on the CQI information and the estimated noise and interference for the uplink; and
estimating noise and interference for the downlink based on the estimated noise and interference for the uplink and the asymmetry, wherein the at least one modulation and coding scheme is determined based on the estimated noise and interference for the downlink.
2. An apparatus for a wireless communication system utilizing time division duplexing (TDD), comprising:
at least one processor configured to:
receive a sounding reference signal on an uplink;
determine a precoding matrix for data transmission on a downlink, based on the sounding reference signal;
determine at least one modulation and coding scheme for the data transmission on the downlink, based on the sounding reference signal;
send the data transmission on the downlink based on the precoding matrix and the at least one modulation and coding scheme;
receive channel quality indicator (CQI) information indicative of channel quality of the downlink;
estimate noise and interference for the uplink based on the sounding reference signal;
determine asymmetry of noise and interference for the downlink and the uplink based on the CQI information and the estimated noise and interference for the uplink;
estimate noise and interference for the downlink based on the estimated noise and interference for the uplink and the asymmetry; and
determine the at least one modulation and coding scheme based on the estimated noise and interference for the downlink.
3. A method of receiving data in a wireless communication system utilizing time division duplexing (TDD), comprising:
sending a sounding reference signal on an uplink;
receiving a data transmission sent on a downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme, the precoding matrix and the at least one modulation and coding scheme determined by the Node B for the data transmission on the downlink based on the sounding reference signal;
generating channel quality indicator (CQI) information indicative of channel quality of the downlink; and
sending the CQI information to the Node B, wherein the at least one modulation and coding scheme is determined by the Node B based further on asymmetry of noise and interference for the downlink and the uplink, and wherein the asymmetry is determined by the Node B based on the CQI information and the sounding reference signal.
4. An apparatus for a wireless communication system utilizing time division duplexing (TDD), comprising:
at least one processor configured to:
send a sounding reference signal on an uplink;
receive a data transmission sent on a downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme, the precoding matrix and the at least one modulation and coding scheme determined by the Node B for the data transmission on the downlink based on the sounding reference signal;
generate channel quality indicator (CQI) information indicative of channel quality of the downlink; and
send the CQI information to the Node B, wherein the at least one modulation and coding scheme is determined by the Node B based further on asymmetry of noise and interference for the downlink and the uplink, and wherein the asymmetry is determined by the Node B based on the CQI information and the sounding reference signal.
5. An apparatus for a wireless communication system utilizing time division duplexing (TDD), comprising:
means for receiving a sounding reference signal on an uplink;
means for determining a precoding matrix for data transmission on a downlink, based on the sounding reference signal;
means for determining at least one modulation and coding scheme for the data transmission on the downlink, based on the sounding reference signal;
means for sending the data transmission on the downlink based on the precoding matrix and the at least one modulation and coding scheme;
means for receiving channel quality indicator (CQI) information indicative of channel quality of the downlink;
means for estimating noise and interference for the uplink based on the sounding reference signal;
means for determining asymmetry of noise and interference for the downlink and the uplink based on the CQI information and the estimated noise and interference for the uplink; and
means for estimating noise and interference for the downlink based on the estimated noise and interference for the uplink and the asymmetry, wherein the at least one modulation and coding scheme is determined based on the estimated noise and interference for the downlink.
6. A computer program product, comprising:
a non-transitory computer-readable medium comprising:
code for receiving a sounding reference signal on an uplink;
code for determining a precoding matrix for data transmission on a downlink, based on the sounding reference signal;
code for determining at least one modulation and coding scheme for the data transmission on the downlink, based on the sounding reference signal;
code for sending the data transmission on the downlink based on the precoding matrix and the at least one modulation and coding scheme;
code for receiving channel quality indicator (CQI) information indicative of channel quality of the downlink;
code for estimating noise and interference for the uplink based on the sounding reference signal;
code for determining asymmetry of noise and interference for the downlink and the uplink based on the CQI information and the estimated noise and interference for the uplink; and
code for estimating noise and interference for the downlink based on the estimated noise and interference for the uplink and the asymmetry, wherein the at least one modulation and coding scheme is determined based on the estimated noise and interference for the downlink.
7. An apparatus for a wireless communication system utilizing time division duplexing (TDD), comprising:
means for sending a sounding reference signal on an uplink;
means for receiving a data transmission sent on a downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme, the precoding matrix and the at least one modulation and coding scheme determined by the Node B for data transmission on the downlink based on the sounding reference signal;
means for generating channel quality indicator (CQI) information indicative of channel quality of the downlink; and
means for sending the CQI information to the Node B, wherein the at least one modulation and coding scheme is determined by the Node B based further on asymmetry of noise and interference for the downlink and the uplink, and wherein the asymmetry is determined by the Node B based on the CQI information and the sounding reference signal.
8. A computer program product, comprising:
a non-transitory computer-readable medium comprising:
code for sending a sounding reference signal on an uplink;
code for receiving a data transmission sent on a downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme, the precoding matrix and the at least one modulation and coding scheme determined by the Node B for the data transmission on the downlink based on the sounding reference signal;
code for generating channel quality indicator (CQI) information indicative of channel quality of the downlink; and
code for sending the CQI information to the Node B, wherein the at least one modulation and coding scheme is determined by the Node B based further on asymmetry of noise and interference for the downlink and the uplink, and wherein the asymmetry is determined by the Node B based on the CQI information and the sounding reference signal.