Synchronization for cooperative spatial multiplexing MIMO-OFDM systems in multipath fading environments

In the cooperative spatial multiplexing MIMO-OFDM systems in multipath fading environments, the streams from different transmit antennas are not aligned in the time domain, and have different frequency offsets. The preambles and synchronization algorithms in the centralized MIMO-OFDM systems can no longer apply. A new preamble structure is proposed for this system, and the corresponding timing and frequency offset estimation algorithms are also presented. The performance of the proposed frequency offset estimation algorithm is derived, and the theoretical limits are given. The simulation shows that the proposed algorithm can estimate the timing and frequency offsets efficiently in the cooperative spatial multiplexing MIMO-OFDM systems.