Zero correlation zone (ZCZ) code assisted frame start detector with combining strategy for 2x2 MIMO-OFDM systems

This paper investigates the performance of frame- start detector (FSD) for MIMO-OFDM system with zero correlation zone (ZCZ) code preamble, assuming transmission over a relatively fast fading mobile wireless channel. The channel coefficients are allowed to vary within the duration of an OFDM symbol. It has been reported that the said method fails to achieve satisfactory performance in terms of the achievable probability of correct detection. The main reason for this poor performance is the large cross-correlation values which occur outside the ZCZ. A strategy based on exploiting the output of the two ZCZ code matched filters is proposed to mitigate this problem. We will prove through computer simulations that this strategy achieves desirable effect in raising the probability of correct detection from approximately 80% to 95% for SNR=0dB with a normalized Doppler frequency of 10^-3.