Joint blind channel and carrier frequency offset estimation in orthogonally space-time block coded mimo systems

The problem of joint channel and carrier frequency offset (CFO) estimation is considered in the context of multiple-input multiple-output (MIMO) communication systems that use orthogonal space-time-block codes (OSTBCs). A new blind approach is proposed to jointly estimate the channel matrix and the CFO. Our technique is based on a relaxed version of maximum likelihood (ML) estimator that ignores the finite alphabet constraint. Using such an approach, we show that the joint channel and CFO estimation problem is equivalent to finding the parameter estimates that maximize the principal eigenvalue of a certain data dependent matrix. Simulation results demonstrate that, despite relaxing the finite alphabet constraint, the performance of the proposed blind detection scheme can approach that of the coherent receiver, provided that there are sufficient data blocks available per channel realization.