Bezout equalization for STBC-MIMO systems

Space-Time Blocking Coding (STBC) has become very popular as an efficient diversity creation technique. With extra transmission redundancies introduced, the receiver performance can be significantly improved via STBC. In this paper, we study the signal recovery problem for a physical Multiple-Input-Multiple-Output (MIMO) channel via an inverse FIR filterbank together with STBC technique. It can be formulated within a multirate polyphase framework to reach an equivalent virtual MIMO system. It is shown that such a system enables equalization of ill conditioned MIMO channels and can offer performance superior to that with direct equalizations. Based on Generalized Bezout Identity theorems, the recoverability conditions are established. We also address the design problem for optimal noise resilience, which is critical from practical perspective. Furthermore, STBC can flexibly reduce the transmission rate to enhance the equalization SNR. The roles of different STBC and equalizer parameters are analyzed for the optimal tradeoff among transmission rate, diversity gain, and implementation complexity.