CODING AND MULTIPLEXING OF CONTROL INFORMATION IN A WIRELESS COMMUNICATION SYSTEM

• US 20090129259A1
• Filed: 08/12/2008
• Published: 05/21/2009
• Est. Priority Date: 08/13/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malladi, Durga Prasad, Montojo, Juan, Kim, Byoung-Hoon, Sarkar, Sandip
• Granted Patent: US 8,503,375 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path

Abstract

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.

Claims

1. A method of sending control information in a wireless communication system, comprising:

spreading control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data; and

spreading the frequency spread data across time with an orthogonal sequence to obtain output data for the control information.

2. The method of claim 1, wherein the spreading the control information across frequency comprises spreading the control information across S subcarriers with an S-point DFT to obtain the frequency spread data comprising S frequency-domain symbols for the S subcarriers, where S is greater than one.

3. The method of claim 2, wherein the spreading the frequency spread data across time comprises spreading the S frequency-domain symbols with the orthogonal sequence of length L to obtain the output data comprising L sets of S output symbols for L symbol periods, where L is greater than one.

4. The method of claim 1, further comprising:

encoding the control information based on a block code to obtain coded data, and wherein the spreading the control information across frequency comprises spreading the coded data across frequency to obtain the frequency spread data.

5. The method of claim 1, wherein the control information comprises acknowledgement (ACK) information and channel quality indicator (CQI) information, the method further comprising:

jointly encoding the ACK information and the CQI information based on a block code to obtain coded data, and wherein the spreading the control information across frequency comprises spreading the coded data across frequency to obtain the frequency spread data.

6. The method of claim 1, further comprising:

determining an acknowledgement (ACK) value for each of N hybrid automatic repeat request (HARQ) processes, where N is greater than one; and

generating ACK information based on N ACK values for the N HARQ processes, wherein the control information comprises the ACK information.

7. The method of claim 6, wherein the generating the ACK information comprises jointly coding the N ACK values for the N HARQ processes to obtain the ACK information.

8. The method of claim 6, wherein the determining the ACK value for each HARQ process comprises setting the ACK value for each HARQ process to one of Q possible values, where Q is greater than one, and wherein the generating the ACK information comprises jointly coding the N ACK values to obtain N_ACK bits for the ACK information, where N_ACK=┌

log₂(Q^N)┐ and

┌

┌

denotes a ceiling operator.

9. The method of claim 6, wherein one codeword is sent for each of the N HARQ processes, and wherein the ACK value for each HARQ process is set to a first value if an assignment is not received, to a second value if the codeword is decoded correctly, or to a third value if the codeword is decoded in error.

10. The method of claim 6, wherein first and second codewords are sent for each of the N HARQ processes, and wherein the ACK value for each HARQ process is set to a first value if an assignment is not received, to a second value if the first and second codewords are decoded correctly, to a third value if only the first codeword is decoded correctly, to a fourth value if only the second codeword is decoded correctly, or to a fifth value if the first and second codewords are decoded in error.

11. The method of claim 6, further comprising:

receiving codewords for the N HARQ processes in N downlink subframes; and

sending the output data in one of M uplink subframes, wherein the N downlink subframes and the M uplink subframes are time division duplexed.

12. The method of claim 1, wherein the control information comprises acknowledgement (ACK) information, or channel quality indicator (CQI) information, or both ACK and CQI information.

13. An apparatus for wireless communication, comprising:

at least one processor configured to spread control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data, and to spread the frequency spread data across time with an orthogonal sequence to obtain output data for the control information.

14. The apparatus of claim 13, wherein the at least one processor is configured to spread the control information across S subcarriers with an S-point DFT to obtain the frequency spread data comprising S frequency-domain symbols for the S subcarriers, where S is greater than one.

15. The apparatus of claim 13, wherein the at least one processor is configured to determine an acknowledgement (ACK) value for each of N hybrid automatic repeat request (HARQ) processes, where N is greater than one, and to generate ACK information based on N ACK values for the N HARQ processes, and wherein the control information comprises the ACK information.

16. The apparatus of claim 15, wherein the at least one processor is configured to jointly code the N ACK values to obtain the ACK information.

17. The apparatus of claim 15, wherein the at least one processor is configured to receive codewords for the N HARQ processes in N downlink subframes, and to send the output data in one of M uplink subframes, wherein the N downlink subframes and the M uplink subframes are time division duplexed.

18. An apparatus for a wireless communication system, comprising:

means for spreading control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data; and

means for spreading the frequency spread data across time with an orthogonal sequence to obtain output data for the control information.

19. The apparatus of claim 18, wherein the means for spreading the control information across frequency comprises means for spreading the control information across S subcarriers with an S-point DFT to obtain the frequency spread data comprising S frequency-domain symbols for the S subcarriers, where S is greater than one.

20. The apparatus of claim 18, further comprising:

means for determining an acknowledgement (ACK) value for each of N hybrid automatic repeat request (HARQ) processes, where N is greater than one; and

means for generating ACK information based on N ACK values for the N HARQ processes, wherein the control information comprises the ACK information.

21. The apparatus of claim 20, wherein the means for generating the ACK information comprises means for jointly coding the N ACK values to obtain the ACK information.

22. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to spread control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data, and

code for causing the at least one computer to spread the frequency spread data across time with an orthogonal sequence to obtain output data for the control information.

23. A method of receiving control information in a wireless communication system, comprising:

despreading received data across time with an orthogonal sequence to obtain time despread data; and

despreading the time despread data across frequency with an inverse discrete Fourier transform (IDFT) to obtain despread symbols for control information.

24. The method of claim 23, wherein the despreading the time despread data across frequency comprises despreading the time despread data across S subcarriers with an S-point IDFT to obtain S despread symbols, where S is greater than one.

25. The method of claim 23, further comprising:

decoding the despread symbols based on a block code to obtain decoded control information.

26. The method of claim 23, further comprising:

determining an acknowledgement (ACK) value for each of N hybrid automatic repeat request (HARQ) processes based on the despread symbols, where N is greater than one.

27. The method of claim 26, further comprising:

sending codewords for the N HARQ processes in N downlink subframes; and

obtaining the received data in one of M uplink subframes, wherein the N downlink subframes and the M uplink subframes are time division duplexed.

28. The method of claim 23, wherein the control information comprises acknowledgement (ACK) information, or channel quality indicator (CQI) information, or both ACK and CQI information.

29. An apparatus for wireless communication, comprising:

at least one processor configured to despread received data across time with an orthogonal sequence to obtain time despread data, and to despread the time despread data across frequency with an inverse discrete Fourier transform (IDFT) to obtain despread symbols for control information.

30. The apparatus of claim 29, wherein the at least one processor is configured to despread the time despread data across S subcarriers with an S-point IDFT to obtain S despread symbols, where S is greater than one.

31. The apparatus of claim 29, wherein the at least one processor is configured to determine an acknowledgement (ACK) value for each of N hybrid automatic repeat request (HARQ) processes based on the despread symbols, where N is greater than one.

32. The apparatus of claim 31, wherein the at least one processor is configured to send codewords for the N HARQ processes in N downlink subframes, and to obtain the received data in one of M uplink subframes, wherein the N downlink subframes and the M uplink subframes are time division duplexed.

33. A method for wireless communication, comprising:

processing first control information based on a first coding and multiplexing scheme utilizing code division multiplexing in both time domain and frequency domain; and

processing second control information based on a second coding and multiplexing scheme utilizing code division multiplexing in the time domain and spreading in the frequency domain.

34. The method of claim 33, wherein for the first coding and multiplexing scheme, the code division multiplexing in the time domain is achieved by spreading across time with an orthogonal sequence, and the code division multiplexing in the frequency domain is achieved with different cyclic shifts of a reference signal sequence.

35. The method of claim 33, wherein for the second coding and multiplexing scheme, the code division multiplexing in the time domain is achieved by spreading across time with an orthogonal sequence, and the spreading in the frequency domain is achieved with a discrete Fourier transform (DFT).

36. The method of claim 33, wherein the processing the first control information based on the first coding and multiplexing scheme comprises

generating a modulation symbol based on the first control information,

modulating a reference signal sequence with the modulation symbol to obtain a modulated reference signal sequence, and

spreading the modulated reference signal sequence across time with an orthogonal sequence.

37. The method of claim 33, wherein the processing the second control information based on the second coding and multiplexing scheme comprises

spreading the second control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data, and

spreading the frequency spread data across time with an orthogonal sequence.

38. The method of claim 33, wherein the processing the first control information based on the first coding and multiplexing scheme comprises

despreading received data across time with an orthogonal sequence to obtain time despread data,

correlating the time despread data with a reference signal sequence to obtain correlation results, and

recovering the first control information based on the correlation results.

39. The method of claim 33, wherein the processing the second control information based on the second coding and multiplexing scheme comprises

despreading received data across time with an orthogonal sequence to obtain time despread data,

despreading the time despread data across frequency with an inverse discrete Fourier transform (IDFT) to obtain frequency despread data, and

recovering the second control information based on the frequency despread data.

40. The method of claim 33, wherein the first control information comprises acknowledgement (ACK) information for one hybrid automatic repeat request (HARQ) process, and wherein the second control information comprises ACK information for multiple HARQ processes.

41. The method of claim 33, wherein the first control information comprises acknowledgement (ACK) information, and wherein the second control information comprises channel quality indicator (CQI) information or both ACK information and CQI information.

42. An apparatus for wireless communication, comprising:

at least one processor configured to process first control information based on a first coding and multiplexing scheme utilizing code division multiplexing in both time domain and frequency domain, and to process second control information based on a second coding and multiplexing scheme utilizing code division multiplexing in the time domain and spreading in the frequency domain.

43. The apparatus of claim 42, wherein the at least one processor is configured to generate a modulation symbol based on the first control information, to modulate a reference signal sequence with the modulation symbol to obtain a modulated reference signal sequence, and to spread the modulated reference signal sequence across time with an orthogonal sequence.

44. The apparatus of claim 42, wherein the at least one processor is configured to spread the second control information across frequency with a discrete Fourier transform (DFT) to obtain frequency spread data, and to spread the frequency spread data across time with an orthogonal sequence.

45. The apparatus of claim 42, wherein the at least one processor is configured to despread received data across time with an orthogonal sequence to obtain time despread data, to correlate the time despread data with a reference signal sequence to obtain correlation results, and to recover the first control information based on the correlation results.

46. The apparatus of claim 42, wherein the at least one processor is configured to despread received data across time with an orthogonal sequence to obtain time despread data, to despread the time despread data across frequency with an inverse discrete Fourier transform (IDFT) to obtain frequency despread data, and to recover the second control information based on the frequency despread data.

47. A method of sending data in a wireless communication system utilizing time division duplexing (TDD), comprising:

receiving a sounding reference signal on uplink;

determining a precoding matrix based on the sounding reference signal;

determining at least one modulation and coding scheme based on the sounding reference signal; and

sending a data transmission on downlink based on the precoding matrix and the at least one modulation and coding scheme.

48. The method of claim 47, further comprising:

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.

49. 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 uplink, to determine a precoding matrix based on the sounding reference signal, to determine at least one modulation and coding scheme based on the sounding reference signal, and to send a data transmission on downlink based on the precoding matrix and the at least one modulation and coding scheme.

50. The apparatus of claim 49, wherein the at least one processor is configured to receive channel quality indicator (CQI) information indicative of channel quality of the downlink, to estimate noise and interference for the uplink based on the sounding reference signal, to 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, to estimate noise and interference for the downlink based on the estimated noise and interference for the uplink and the asymmetry, and to determine the at least one modulation and coding scheme based on the estimated noise and interference for the downlink.

51. A method of receiving data in a wireless communication system utilizing time division duplexing (TDD), comprising:

sending a sounding reference signal on uplink; and

receiving a data transmission sent on downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme determined by the Node B based on the sounding reference signal.

52. The method of claim 51, further comprising:

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.

53. 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 uplink, and to receive a data transmission sent on downlink by a Node B based on a precoding matrix and at least one modulation and coding scheme determined by the Node B based on the sounding reference signal.

54. The apparatus of claim 53, wherein the at least one processor is configured to generate channel quality indicator (CQI) information indicative of channel quality of the downlink, and to 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.