Semi-blind joint frequency offset and channel estimation in MIMO OFDM systems

Abstract

A semi-blind method for joint estimation of the frequency offset and the channel in an MIMO OFDM system is presented in this paper. Estimation is achieved in three successive steps. First, the channel containing the frequency-offset component is estimated by means of subspace techniques and few pilots. The result is then used in the second step, which is cyclostationarity-based, to obtain the frequency offset. Finally, the channel can be achieved by removing the frequency-offset component from the result of the first step. Mathematical deduction and simulation results are both shown that the proposed method is effective. And the number of pilots required by this algorithm equals the number of transmit antennas, which is significantly less than that in the pure-pilot-based channel estimation algorithm.