SEMI-BLIND channel identification and symbol estimation for asynchronous MIMO systems

SEMI-BLIND channel identification and symbol estimation for asynchronous MIMO systems are considered in this paper. MIMO channels are estimated from the second order statistics of the received signals subject to an ambiguity matrix and unknown time delays. Then a small number of pilot symbols are used to resolve the ambiguity matrix and time delays. A two-step symbol estimation method, which estimates the channels before recovering the symbols, is proposed. Only upper bounds for the channel orders and time delays are needed for implementing the algorithms. Neither knowledge of real channel orders nor precise synchronization of different users is required, which makes the algorithm applicable to practical MIMO systems. © 2005 IEEE.published_or_final_versio