Design of a novel frequency division scheme for DCSK chaos communication system

In this paper, a high efficient differential chaos shift keying (DCSK) based on frequency division multiplexing (FDM) communication system, namely FDM-HEDCSK is proposed. The scheme has two branches and a serial-parallel converter to achieve four attainable bit rates and improve communication security in comparison to DCSK. In this scheme, the combination of two chaos signals is used as the reference signal, on which four bits data are modulated and each transmitter branch transmits its signals together by FDM. The bit error rate (BER) performance is derived based on Gaussian approximation in AWGN channel. Moreover, compared with several systems such as DCSK, correlation delay shift keying (CDSK), with typical spreading factors the BER performance of the proposed scheme can always outperform them at reasonable signal-to-noise ratio (SNR).