초록 ▼

A receiver suppresses co-channel interference (CCI) from other transmitters and intersymbol interference (ISI) due to channel distortion using “virtual” antennas. The virtual antennas may be formed by (1) oversampling a received signal for each actual antenna at the receiver and/or (1)

A receiver suppresses co-channel interference (CCI) from other transmitters and intersymbol interference (ISI) due to channel distortion using “virtual” antennas. The virtual antennas may be formed by (1) oversampling a received signal for each actual antenna at the receiver and/or (1) decomposing a sequence of complex-valued samples into a sequence of inphase samples and a sequence of quadrature samples. In one design, the receiver includes a pre-processor, an interference suppressor, and an equalizer. The pre-processor processes received samples for at least one actual antenna and generates at least two sequences of input samples for each actual antenna. The interference suppressor suppresses co-channel interference in the input sample sequences and provides at least one sequence of CCI-suppressed samples. The equalizer performs detection on the CCI-suppressed sample sequence(s) and provides detected bits. The interference suppressor and equalizer may be operated for one or multiple iterations.

대표청구항 ▼

What is claimed is: 1. A receiver comprising: a pre-processor operative to process samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna and a dif

What is claimed is: 1. A receiver comprising: a pre-processor operative to process samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna and a different one of the input samples generated by the oversampling from each sample period is included in each of the plurality of sequences of input samples, and wherein the sequences of input samples are offset from one another by a fraction of the sample period; an interference suppressor operative to suppress co-channel interference (CCI) in the plurality of sequences of input samples and to provide at least one sequence of CCI-suppressed samples; and an equalizer operative to perform detection on the at least one sequence of CCI-suppressed samples. 2. The receiver of claim 1, wherein the pre-processor is operative to provide at least one sequence of early samples and at least one sequence of late samples for the antenna, the early and late samples being offset by a half sample period. 3. The receiver of claim 1, wherein the pre-processor is operative to provide at least one sequence of inphase samples and at least one sequence of quadrature samples for the antenna, the inphase and quadrature samples corresponding to real and imaginary parts, respectively, of complex-valued samples. 4. The receiver of claim 1, wherein the pre-processor comprises: a filter operative to filter the received samples to generate a plurality of sequences of intermediate samples; and a rotator operative to perform phase rotation on the plurality of sequences of intermediate samples to generate the plurality of sequences of input samples. 5. The receiver of claim 1, wherein the interference suppressor comprises a multiple-input multiple-output (MIMO) filter operative to filter the plurality of sequences of input samples with a plurality of weights to generate the at least one sequence of CCI-suppressed samples, the plurality of weights being derived to suppress the co-channel interference in the plurality of sequences of input samples. 6. The receiver of claim 5, wherein the MIMO filter comprises a plurality of finite impulse response (FIR) filters operative to filter the plurality of sequences of input samples. 7. The receiver of claim 6, wherein each of the plurality of FIR filters is operative to filter a respective sequence of input samples with a respective set of weights. 8. The receiver of claim 1, wherein the interference suppressor comprises: a channel estimator operative to derive at least one channel estimate based on the plurality of sequences of input samples; a signal estimator operative to derive at least one desired signal estimate based on the at least one channel estimate; a computation unit operative to compute weights used to suppress co-channel interference; and a multiple-input multiple-output (MIMO) filter operative to filter the plurality of sequences of input samples with the weights to generate the at least one sequence of CCI-suppressed samples. 9. The receiver of claim 8, wherein the channel estimator is operative to derive the at least one channel estimate using a least-squares (LS) criterion. 10. The receiver of claim 8, wherein the computation unit is operative to compute the weights for the MIMO filter using a minimum mean square error (MMSE) criterion. 11. The receiver of claim 8, wherein the channel estimator, the signal estimator, the computation unit, and the MIMO filter are operated for a plurality of iterations. 12. The receiver of claim 1, wherein the equalizer comprises: a channel estimator operative to derive at least one channel estimate based on the at least one sequence of CCI-suppressed samples; and a detector operative to perform detection on the at least one sequence of CCI-suppressed samples with the at least one channel estimate. 13. The receiver of claim 12, wherein the detector is a maximum likelihood sequence estimator (MLSE). 14. The receiver of claim 1, wherein the interference suppressor is operative to provide at least two sequences of CCI-suppressed samples, and wherein the equalizer comprises: a channel estimator operative to derive at least two channel estimates based on the at least two sequences of CCI-suppressed samples; a signal estimator operative to derive at least two desired signal estimates based on the at least two channel estimates; a computation unit operative to compute a noise correlation matrix based on the at least two desired signal estimates and the at least two sequences of CCI-suppressed samples; and a detector operative to perform detection on the at least two sequences of CCI-suppressed samples with the at least two channel estimates and the noise correlation matrix. 15. The receiver of claim 14, wherein the detector is a maximum likelihood sequence estimator (MLSE) and is operative to compute branch metrics using the noise correlation matrix. 16. The receiver of claim 1, further comprising: a selector operative to receive detected bits from the equalizer and a training sequence and to provide reference bits for the interference suppressor and the equalizer. 17. The receiver of claim 1, wherein the interference suppressor and the equalizer are operated for a plurality of iterations. 18. The receiver of claim 17, wherein the interference suppressor is operative to suppress the co-channel interference based on a training sequence for a first iteration and based on detected bits from the equalizer and the training sequence for each subsequent iteration. 19. The receiver of claim 17, wherein the equalizer is operative to perform detection based on a training sequence for a first iteration and based on detected bits from the equalizer and the training sequence for each subsequent iteration. 20. The receiver of claim 1, further comprising: a filter operative to filter soft decisions generated based on an output of the equalizer and to provide filtered symbols; a threshold compare unit operative to compare the filtered symbols against a threshold and to provide comparison results; and a selector operative to provide reference bits for the interference suppressor and the equalizer based on the comparison results. 21. The receiver of claim 20, wherein the filter is operative to filter the soft decisions with a plurality of weights derived based on a channel impulse response estimate. 22. The receiver of claim 1, further comprising: a receive data processor operative to process an output of the equalizer to obtain decoded data; and a transmit data processor operative to process the decoded data to generate re-encoded bits, wherein the equalizer is operative to perform detection based on the re-encoded bits. 23. The receiver of claim 22, wherein the interference suppressor is operative to suppress co-channel interference based on the encoded bits. 24. The receiver of claim 1, further comprising: a receive data processor operative to process an output of the equalizer to generate soft output symbols for a soft-input soft-output (SISO) detector formed by the interference suppressor and the equalizer, wherein the SISO detector and the receive data processor are operated for a plurality of iterations. 25. A receiver comprising: a pre-processor operative to process samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna, a different one of the input samples generated by the oversampling from each sample period is included in each of the plurality of sequences of input samples, and by decomposing complex-valued samples into inphase and quadrature samples, and wherein the sequences of input samples are offset from one another by a fraction of the sample period; an interference suppressor operative to suppress co-channel interference (CCI) in the plurality of sequences of input samples and to provide at least one sequence of CCI-suppressed samples; and an equalizer operative to perform detection on the at least one sequence of CCI-suppressed samples. 26. A method of receiving data in a communication system, comprising: processing samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna and a different one of the input samples generated by the oversampling from each sample period is included in each of the plurality of sequences of input samples, and wherein the sequences of input samples are offset from one another by a fraction of the sample period; suppressing co-channel interference (CCI) in the plurality of sequences of input samples to generate at least one sequence of CCI-suppressed samples; and performing detection on the at least one sequence of CCI-suppressed samples. 27. The method of claim 26, wherein the processing the samples for the antenna comprises: filtering the received samples to obtain a plurality of sequences of intermediate samples; and performing phase rotation on the plurality of sequences of intermediate samples to generate the plurality of sequences of input samples. 28. The method of claim 26, wherein the suppressing co-channel interference in the plurality of sequences of input samples comprises: computing a plurality of weights used to suppress co-channel interference; and filtering the plurality of sequences of input samples with the plurality of weights to generate the at least one sequence of CCI-suppressed samples. 29. The method of claim 26, wherein the suppressing co-channel interference in the plurality of sequences of input samples comprises: deriving at least one channel estimate based on the plurality of sequences of input samples; deriving at least one desired signal estimate based on the at least one channel estimate; computing weights used to suppress co-channel interference; and filtering the plurality of sequences of input samples with the weights to generate the at least one sequence of CCI-suppressed samples. 30. The method of claim 26, wherein the performing detection on the at least one sequence of CCI-suppressed samples comprises: deriving a channel estimate based on the at least one sequence of CCI-suppressed samples; and performing detection on the at least one sequence of CCI-suppressed samples with the channel estimate. 31. The method of claim 26, wherein at least two sequences of CCI-suppressed samples are generated, and wherein the performing detection on the at least two sequences of CCI-suppressed samples comprises: deriving at least two channel estimates based on the at least two sequences of CCI-suppressed samples; deriving at least two desired signal estimates based on the at least two channel estimates; computing a noise correlation matrix based on the at least two desired signal estimates and the at least two sequences of CCI-suppressed samples; and performing detection on the at least two sequences of CCI-suppressed samples with the at least two channel estimates and the noise correlation matrix. 32. The method of claim 26, further comprising: performing co-channel interference suppression and detection for a plurality of iterations. 33. The method of claim 26, further comprising: determining quality of detected bits generated by the detection; generating reference bits based on the determined quality of the detected bits; and using the reference bits for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 34. The method of claim 26, further comprising: decoding detected bits generated by the detection to obtain decoded data; encoding the decoded data to obtain re-encoded bits; and using the re-encoded bits for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 35. The method of claim 26, further comprising: decoding an output generated by the detection to obtain soft output symbols; and using the soft output symbols for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 36. An apparatus in a communication system, comprising: means for processing samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna and a different one of the input samples generated by the oversampling from each sample period is included in each of the plurality of sequences of input samples, and wherein the sequences of input samples are offset from one another by a fraction of the sample period; means for suppressing co-channel interference (CCI) in the plurality of sequences of input samples to generate at least one sequence of CCI-suppressed samples; and means for performing detection on the at least one sequence of CCI-suppressed samples. 37. The apparatus of claim 26, wherein the means for processing the received samples for the at least one antenna comprises: means for filtering the received samples to obtain a plurality of sequences of intermediate samples; and means for performing phase rotation on the plurality of sequences of intermediate samples to generate the plurality of sequences of input samples. 38. The apparatus of claim 36, wherein the means for suppressing co-channel interference in the plurality of sequences of input samples comprises: means for computing a plurality of weights used to suppress co-channel interference; and means for filtering the plurality of sequences of input samples with the plurality of weights to generate the at least one sequence of CCI-suppressed samples. 39. The apparatus of claim 36, wherein the means for suppressing co-channel interference in the plurality of sequences of input samples comprises: means for deriving at least one channel estimate based on the plurality of sequences of input samples; means for deriving at least one desired signal estimate based on the at least one channel estimate; means for computing weights used to suppress co-channel interference; and means for filtering the plurality of sequences of input samples with the weights to generate the at least one sequence of CCI-suppressed samples. 40. The apparatus of claim 36, wherein the means for performing detection on the at least one sequence of CCI-suppressed samples comprises: means for deriving a channel estimate based on the at least one sequence of CCI-suppressed samples; and means for performing detection on the at least one sequence of CCI-suppressed samples with the channel estimate. 41. The apparatus of claim 36, wherein at least two sequences of CCI-suppressed samples are generated, and wherein the means for performing detection on the at least two sequences of CCI-suppressed samples comprises: means for deriving at least two channel estimates based on the at least two sequences of CCI-suppressed samples; means for deriving at least two desired signal estimates based on the at least two channel estimates; means for computing a noise correlation matrix based on the at least two desired signal estimates and the at least two sequences of CCI-suppressed samples; and means for performing detection on the at least two sequences of CCI-suppressed samples with the at least two channel estimates and the noise correlation matrix. 42. The apparatus of claim 36, further comprising: means for performing co-channel interference suppression and detection for a plurality of iterations. 43. The apparatus of claim 36, further comprising: means for determining quality of detected bits generated by the detection; means for generating reference bits based on the determined quality of the detected bits; and means for using the reference bits for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 44. The apparatus of claim 36, further comprising: means for decoding detected bits generated by the detection to obtain decoded data; means for encoding the decoded data to obtain re-encoded bits; and means for using the re-encoded bits for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 45. The apparatus of claim 36, further comprising: means for decoding an output generated by the detection to obtain soft output symbols; and means for using the soft output symbols for co-channel interference suppression, detection, or both co-channel interference suppression and detection. 46. A computer-program product comprising memory having instructions stored thereon, the instructions comprising: code for processing samples from a signal received at an antenna to generate a plurality of sequences of input samples from the signal, wherein the input samples are generated by oversampling the signal received at the antenna and a different one of the input samples generated by the oversampling from each sample period is included in each of the plurality of sequences of input samples, and wherein the sequences of input samples are offset from one another by a fraction of the sample period; code for suppressing co-channel interference (CCI) in the plurality of sequences of input samples to generate at least one sequence of CCI-suppressed samples; and code for performing detection on the at least one sequence of CCI-suppressed samples.