Performance of MC–CDMA system through Modified Particle Swarm Optimisation algorithm based Turbo Multiuser detection

Orthogonal Frequency Division multiplexing (OFDM) introduces multicarrier concept in Code Division Multiple Access (CDMA) to give rise to novel concept of MC-CDMA system. The MC-CDMA is an efficient technique that mitigates problems like, spectral limitation and distortion due to multipath fading channels. So it is considered as a strong contender for future broadband wireless mobile communication. Advantages of this technique are its robustness in case of multipath propagation, improve security, high data rates and minimize the ISI. Even though, when the orthogonality is lost in OFDM part of MC-CDMA system due to mobile environment, it suffers from multiple access interference (MAI). In this paper a low complexity Modified Particle Swarm Optimisation (MPSO) algorithm based Turbo Multiuser detection is proposed for MC-CDMA system. The MPSO algorithm is combined with Turbo MUD to mitigate MAI and to reduce the complexity of the decoding, by modified cognitive parameter and adjusting the inertia factors. The movement of a particle is illustrated by three components such as dynamic inertia, cognitive and social component in MPSO technique. The cognitive component is modified into best position and worst position, which gives the more efficient optimisation solution for produce better approximation APP information solution. Hence the complexity of the Turbo MUD can be reduced by the virtue of swift convergence of MPSO. The proposed a low complexity MPSO algorithm aided Turbo MUD scheme can provide a better BER performance than other Turbo MUD with a lower computational complexity.