An approach for joint blind space-time equalization and DOA estimation

A multi-stage structure to jointly combat multi-user interference and fading channels is presented. Neither the DOA nor a training sequence is assumed to be available for the receiver. The only assumption is that the transmitted signal satisfies the constant modulus property which is valid for many modulation schemes, and can be exploited by the multimodulus algorithm. Taking advantage of virtual subarrays, the DOA at each stage is estimated and used to compute the next stage input. Each stage operates in two modes, the starting and the tracking mode. Thanks to the adaptive structure, it can deal with time-varying DOAs and channels. Simulation results illustrate the performance of this method.