Fuzzy Based Interference Cancellation Scheme for OFDMA Systems

Orthogonal frequency division multiple access (OFDMA) is a promising multiple access technique for future cellular wideband communication systems. In OFDMA systems, multiple access is achieved by assigning subsets of orthogonal subcarriers to individual users. Hence these systems are less sensitive to inter symbol interference. However, the orthogonality between users´ codes is often disturbed by the carrier frequency offset due to the Doppler effect in fading channels, time delay due to multipath components and poor synchronization at the receiver. This offset results in interference between users in the system. In this paper, a fuzzy based multiuser interference cancellation scheme has been proposed for OFDMA systems. Monte Carlo simulations have been run to simulate the performance of the proposed interference cancellation scheme. It is observed from the results that the proposed scheme outperforms those available in the literature in terms of less bit error rate.