BER Improvement of Chaotic Communication Based OFDM System Using Adaptive Beamforming

Recent advances in wireless communications have made use of CDMA and OFDM techniques to allow for high data rate transmission. Rapid time variations of the wireless communication channel have an effect on the performance of multicarrier modulation. This paper presents the performance improvement of MIMO-OFDM system with a technique which uses chaotic communication system combined with adaptive beamforming in the presence of AWGN channel. The proposed system uses a new wireless communication structure based on two coupled chaotic systems.

Simulation results demonstrate that the proposed system (chaotic based STC-MIMO-OFDM system) has good ability of suppressing interference & hence significantly improves the bit-error rate (BER) performance of the system. It is also observed that the modulation techniques used has its impact on the BER performance to great extent in chaotic based MIMO-OFDM system whereas the impact is negligible in the STTC based MIMO-OFDM system & PN sequence based STC-MIMO-OFDM system. A simulation tool with a graphical user interface which implements these algorithms are also developed to represent the various results in systematic manner.