Lower Bound on the BER of a Decode-and-Forward Relay Network Under Chaos Shift Keying Communication System

This paper carries out the first-ever investigation of the analysis of a cooperative Decode-and-Forward (DF) relay network with Chaos Shift Keying (CSK) modulation. The performance analysis of DF-CSK in this paper takes into account the dynamical nature of chaotic signal, which is not similar to a conventional binary modulation performance computation methodology. The expression of a lower bound bit error rate (BER) is derived in order to investigate the performance of the cooperative system under independently and identically distributed (i.i.d.) Gaussian fading wireless environments. The effect of the non-periodic nature of chaotic sequence leading to a non constant bit energy of the considered modulation is also investigated. A computation approach of the BER expression based on the probability density function of the bit energy of the chaotic sequence, channel distribution, and number of relays is presented. Simulation results prove the accuracy of our BER computation methodology.