Blind channel estimation for MIMO systems with structured transmit delay diversity

In this paper, space-time transmit diversity is exploited to relax the restrictive blind channel identifiability constraints for multiple-input multiple-output (MIMO) systems. First, a simple structured transmit delay diversity scheme is proposed. Unlike existing transmit diversity schemes, in which different antennas transmit delayed, zero-padded, or time reversed versions of the same signal, in the proposed scheme, each antenna transmits an independent data stream and therefore promises higher data rate. Secondly, a second-order statistics based blind channel estimation algorithm is developed for MIMO systems with the structured transmit diversity. The proposed approach involves no pre-equalization, has no limitations on channel zero locations and does not require the MIMO channel matrix to be irreducible. Simulation results demonstrate the robustness and effectiveness of the proposed scheme