CSK based STBC-CDMA System: Design and Performance Evaluation
In this paper, the design of a communication system that combines a Multiple-Input Multiple Output (MIMO) scheme with a Code Division Multiple Access (CDMA) based on chaotic sequence have been discussed. Various design issues pertaining to this arrangement and the Bit Error Rate (BER) performance under Rayleigh fading channel have been investigated. Because of the non-periodic nature of chaotic signals, the signal after passing through the chaotic modulator is characterized by bit energy that can vary from one bit to another. As a result, the expression for the BER requires the computation of an intractable integral. To overcome this problem, the BER expression for a given chaotic map over all possible spreading sequences associated with a given spreading factor has been integrated. A system where the output of a Chaos Shift Keying (CSK) modulation scheme is combined with Space Time Block Code (STBC) for and Alamouti schemes has been considered. The BER computation has been approved by simulation results.