Blind iterative receiver for multiuser MIMO systems

The information capacity of wireless communication systems may be increased dramatically by employing multiple transmit and receive antennas. In this chapter, we consider multiuser wireless communication system, employing multiple transmit and receive antennas. We estimate jointly channel and symbols user-wise by Maximum Likelihood approach (ML) approach. Two models are considered for the symbols of the interferers, corresponding to Gaussian and discrete priors. In the latter case, in which the finite alphabet gets exploited for the MAI symbols, a simplifi- cation for the posterior MAI symbol probabilities is introduced based on Mean Field Theory. Section 3 is devoted to the general principle of the EM algorithm for Maximum Likelihood (ML) estimation. Section 4 describes user-wise channel-symbol estimation with Gaussian prior on MAI. In section 5, we describe user-wise channel-symbol estimation procedure using discrete prior on MAI symbols. Conclusions are drawn in section 6.