Quadrature Chaotic Symbolic OFDM Communication Over Radio Channels

This article introduces a novel modulation technique, namely quadrature chaotic symbolic OFDM (QCSO), that conjugates OFDM (orthogonal frequency division multiplex) and symbolic dynamics chaotic signal communication. The main innovation of QCSO is the use of two orthogonal chaotic signal streams multiplexed through orthogonal carriers to double the transmitted bit rate. A study on the performance of quadrature chaotic symbolic OFDM signals over both AWGN and Rayleigh fading channels is presented. Both FFT- OFDM and Wavelet OFDM are considered and compared against each other. The performance of this new modulation scheme is found to be comparable to traditional modulation techniques. Also, it was also found that Chaotic Wavelet OFDM outperforms Chaotic FFT systems in both AWGN and multipath environment.