A novel pilot-based frequency offset compensation method in MIMO-OFDM Systems

MIMO-OFDM is the promising technique in the future of wireless communications as it combines the properties of Multiple Input Multiple Output (MIMO) systems with those of Orthogonal Frequency Division Multiplexing (OFDM). However, it is very sensitive to frequency offsets which result in inter-carrier interference (ICI). Therefore, to precisely recover the transmitted data, frequency offset compensation is necessary in MIMO-OFDM receivers. This paper mainly focuses on frequency offset estimation and compensation problem. We use channel coefficients to accurately follow all the frequency offsets. In our proposed receiver the initial estimation is done using a polynomial curve fitting method. To improve system performance, an iterative algorithm, i.e. a feedback from the output to the input, is applied. In this way, every single subcarrier in frequency domain is separately compensated for all the frequency offsets that it experiences while passing through the fading channel. Simulation results clearly show that our proposed method precisely recovers the transmitted data symbols in multipath fading channels.