GSLC architecture for sequence detectors using spatial diversity

The role of advanced front-ends including spatial diversity, has been considered as an independent part of peak-distortion equalizers, Wiener and Viterbi equalizers. This involves that the optimum processing to remove point or distributed sources, together with inner and outer intersymbol interference is analyzed independently at the beamformer and at the equalizer stages. Recently, based on extensions of the works performed with forward equalizers and optimal combining in communications systems with spatial diversity, several solutions to the joint design of sequence detectors and spatial combiners have been reported. All these solutions have in common the principle that the optimum design holds the constraint of matching the spatial response of the combiner to the DIR (Desired Impulse Response) of the sequence detector. This work enhances the matched DIR concept with the Generalized Sidelobe Canceller architecture; proving that, for stationary Intersymbol Interference (ISI) for the desired user, the GLSC represents a suitable spatial processing. The GSLC allows continuous updating of the combiner either in order to reject late arrivals and co-channel interferers, without requiring the presence of training sequence or to maximize the effective SNR.