Abstract: The present invention addresses the deficiencies of prior art joint detection techniques by implementing the decision feedback equalizer part of a joint detector in the turbo decoding iteration loop such that joint detection and turbo decoding are performed interactively in a mutual support fashion. Thus, the decoder (230) benefits from ISI and MAI suppressed samples provided by the equalizer, while the decision feedback equalizer is fed with more reliable hard decisions for the transmitted symbols by the turbo decoder.

Abstract: The present invention achieves the benefits of the improved joint detector previously disclosed with significantly less computation by, first, moving the backward substitution computation outside the detector's decoding iteration loop and, second, by moving the input buffer inside the iteration loop. The backward substitution computation is performed initially as part of a joint detection equalization stage prior to entering the decode iteration loop. Then with each decode iteration, the present invention generates a correction signal that is subtracted from the present input signal to produce the next input signal. Each correction signal is generated from a series of differences between the decoded symbols of the current iteration and those in the previous iteration. Thus, the present invention achieves the same performance improvement over conventional joint detectors as the improved joint detector previously disclosed but with dramatically less computational requirements.

Abstract: The present invention addresses the deficiencies of prior art joint detection techniques by implementing the decision feedback equalizer part of a joint detector in the turbo decoding iteration loop such that joint detection and turbo decoding are performed interactively in a mutual support fashion. Thus, the decoder (230) benefits from ISI and MAI suppressed samples provided by the equalizer, while the decision feedback equalizer is fed with more reliable hard decisions for the transmitted symbols by the turbo decoder.

Abstract: A decoder equalizes a turbo coded signal with intersymbol interference by performing a decision-feedback equalization in each iteration of the turbo decoding process. In such iteration process, two recursion processors calculate soft output values for the information bits and the coded bits of the signal as well. Hard output values are derived from the soft output values. A decision feedback equalizer in an iterative loop of the decoder receives the hard output values uses these to provide a correction for the intersymbol interference. Thereafter, the decision feedback signal applies the correction signal to the input signal to minimize the intersymbol interference.