Optimal chaos shift keying communications with correlation decoding

The effect of the chaotic map employed in chaos shift keying (CSK) communication systems is discussed. Based on the exact bit-error rate of a CSK system, the conditions for an optimal map are deduced. One group of asymptotically optimal maps is proposed which has asymptotic performance at the level of the theoretical BPSK lower bound. Simulation results using the optimal maps are provided and compared with commonly used chaotic maps. The proposals show how to design both coherent and non-coherent CSK systems, with spreading factors of two, which have the advantage of being chaotic and have the high performance of BPSK.