Performance analysis of iterative detection for pre-transformed OFDM

Recently, an iterative detection method is proposed for a pre-transformed OFDM system, where significant performance gain is shown to be achieved through linear processing (Z.Lei et al., Apr. 2003). An analytical treatment of the subject is given. The optimum transform design and reconstruction criteria are given to maximize the minimum SNR. In the case when no iteration is applied (i = 0), we compare the effect of the transform on the performance in a channel with and without diversity. Under the assumption that the previous detection is error free, it is shown analytically that the iterative method achieves a diversity advantage of i + 1 in the i^th iteration, thus providing an explanation on its superior performance. Simulations are conducted to corroborate the analysis. Due to the generality of the transform design, the analysis conducted is applicable for other common systems (such as MC-CDMA and SC-FDE systems) as well.