High-data-rate PO-CDSK: a high effective chaotic communication scheme

Abstract

To eliminate the intrasignal interference (ISI), phase-orthogonality correlation-delay-shift-keying (PO-CDSK) alternately chooses quadrature sinusoidal wavelets to modulate the reference signals in different symbol durations and keeps the reference and information-bearing signals orthogonal in one symbol duration. Unfortunately, in PO-CDSK, one data-modulated signal can carry only 1-bit information, resulting in a relatively low data rate. In this brief, the authors design a high-data-rate PO-CDSK system, in which 2-bits information share one time slot but transmitted over the inphase and quadrature channels, respectively. Theoretical BER expression of the proposed system is studied analytically, and simulations are performed over additive white Gaussian noise and Rayleigh multipath fading channels for verification. Results show that, without ISI components, the authors' new system performs much better than differential-chaos-shift-keying (DCSK), CDSK and high-efficiency DCSK systems in BER performance. Besides, the proposed system also achieves doubled spectral and energy efficiencies in comparison with PO-CDSK.