Blind separation of synchronous co-channel digital signals using an antenna array. II. Performance analysis

We have recently proposed a blind maximum likelihood approach for demodulating multiple co-channel digital signals received synchronously at an antenna array. This approach exploits the finite alphabet (FA) property of digital signals to simultaneously estimate the array response and symbol sequence for each signal. We have presented two computationally efficient block algorithms for computing the array response and signal estimates: iterative least-squares with projection (ILSP) and iterative least-squares with enumeration (ILSE). In this paper, we study the performance of these algorithms using both analysis and simulation. We derive the probability of error in detecting the signals under the assumption that the array responses are known. We use this probability to estimate the probability of error in the algorithms. Simulation results confirm that the detection error probability yields a good approximation to the performance of the blind algorithms.