The autocorrelation matching method for distributed MIMO communications over unknown FIR channels

The autocorrelation matching method is a blind signal separation and channel equalization technique for distributed MIMO communication systems over unknown FIR channels using only second order statistics. This method is based on a theoretical discovery, ie, under the condition that the autocorrelation functions of the (multiple) inputs are linearly shift-independent, an input is recovered, up to a unitary factor and a delay, by an output of an MIMO-FIR equalizer if and only if the autocorrelation function of the output matches that of the input. An optimal zero-forcing equalizer is developed to maximize the SNR for the outputs, ie, the recovered inputs. Some preliminary simulation results show that the BER in the recovered inputs is about 3×10^-5 at the SNR=15 dB. This method has the potential to be applied to cellular wireless communications for the purpose of boosting spectrum efficiency or suppressing co-channel interference