Nonparametric interference cancellation and equalization for narrowband TDMA communications via space-time processing

A space-time processing scheme is proposed for TDMA based cellular/PCS communications that cancels co-channel interference while simultaneously equalizing the desired signal. A received training sequence, designed from a PN code, is processed to form a symbol waveform that is built up above the noise and interference. The signal plus interference and interference alone spatial correlation matrices are then estimated facilitating the formation of interference canceling beams. Exploiting a spatial gain against interference and noise, the sampled-spaced channel taps associated with each beam are then accurately estimated from samples taken from the center of the correlator output. Variations in the channel responses and/or interference environment during the desired user's burst of symbols may be tracked via a decision directed version of the proposed scheme. Simulations involving three-ray multipath are presented demonstrating the efficacy of the method.