Optimal Training Design for Channel Estimation in MIMO Single/Multi Carrier Block Transmission Systems

This paper proposes an optimal training sequence framework for general block transmission systems over spatially correlated multiple-input multiple-output (MIMO) frequency selective channels. The pilot design is based on a formulation that minimizes the Bayesian Cramér-Rao bound (BCRB) for the mean squared error (MSE) of channel estimation, and is thus MSE optimal in nature. The novelty of the proposed work lies in development of a generic pilot design scheme applicable to all the four MIMO block transmission systems, namely single carrier cyclic prefix (SC-CP), single carrier zero padded (SC-ZP), multi-carrier zero padded (MC-ZP), and multi-carrier cyclic prefix (MC-CP) systems. Simulation results are presented to illustrate the superior performance of the proposed technique over the conventional pilot sequences, in terms of both MSE as well as bit error rate (BER).