Blind estimation of multiple co-channel digital signals arriving at an antenna array

We propose a novel approach for separating and estimating multiple co-channel digital signals arriving at an antenna array. The spatial response of the antenna array is known imprecisely or unknown. We exploit the discrete-alphabet property of digital signals to simultaneously determine the array response and the bit sequence for each signal. Uniqueness of the estimates is established for signals with BPSK modulation format. This new approach as applicable to an unknown array geometry and propagation environment, which is particularly useful in digital mobile communications. Simulation results demonstrate its promising performance