Two-stage CCI/ISI reduction with space-time processing in TDMA cellular networks

Abstract

A two-stage, space-time digital receiver provides improved estimates of data symbols from a received signal comprising the data symbols, co-channel interference, and intersymbol interference. The first stage uses a space-time linear filter to process the received signal and provide an intermediate signal with substantially reduced co-channel interference content and substantially unaltered intersymbol interference content relative to that of the received signal. The second stage uses a Viterbi equalizer to estimate the data symbols from the intermediate signal. Because the receiver performs Viterbi equalization on the intermediate signal with reduced co-channel interference, its performance is superior to that of receivers that directly Viterbi equalize the received signal. A first embodiment of a receiver according to the present invention determines the weight coefficient matrix for the linear filter by applying MMSE criteria to the error between the intermediate signal and a reference signal derived from the convolution of known training symbols with a first set of estimated channel vectors. The first embodiment also derives a second set of estimated channel vectors from the intermediate signal for the Viterbi equalizer. A second embodiment jointly determines the coefficients for the linear filter and estimated channel vector for the Viterbi equalizer, respectively, by maximizing a single SINR objective function.

Dependencies are inferred from the claim text.