Reference-Modulated DCSK: A Novel Chaotic Communication Scheme

In this brief, a reference-modulated differential chaos shift keying (DCSK) (RM-DCSK) is proposed for reliable and high-data-rate chaotic communication with low cost. In this scheme, the chaotic wavelet sent in either the first or second slot of each frame not only carries one bit of data but also serves as the message bearer of the data bit transmitted in its following time slot. Without any extra cost in decoding complexity, RM-DCSK can achieve doubled attainable bit rate and improved communication security in comparison to DCSK. The bit error rate (BER) performance of this new scheme is derived based on Gaussian approximation. Moreover, relevant simulation results in the additive white Gaussian noise channel are also given and compared with those of correlation delay shift keying (CDSK), DCSK, frequency-modulated DCSK, and high-efficiency DCSK schemes, which shows that the BER performance of our system is always superior to that of CDSK and it can even outperform DCSK under certain E_b/N₀ levels or with large spreading factors.