DefinePK

Abstract

The paper describes the mathematical model of a novel scheme 2x-Mod (1)-Chaotic-Collaborative-CDMA (2XM1-CCCDMA) and analyzes its bit-error-rate (BER) performance under Rayleigh fading. The row elements of an NxN matrix of mutually orthogonal chaotic sequences generated by the 2x-Mod(1) one-dimensional (1D) chaotic-map is used as the ‘shared-spreading-sequences’ for a group of collaborating users. The ith row of the NxN matrix determines the spreading sequence for the collaborating users of the ith group in 2XM1-CCCDMA. The proposed scheme also utilizes a chaotic-pilot for the synchronization of the users at group level and addresses the capacity and security requirements for imminent wireless systems. The simulation results show the performance comparison of BER with conventional and collaborative CDMA schemes. The proposed scheme eliminates the constraints in security and user-capacity outperforming existing multi-user-detection (MUD) schemes and espouses a fourfold increase in the number of users with good BER performance under Rayleigh fading.