An improved scheme for noise reduction to DCSK based on its retransmission characteristic

In chaos communication schemes, the differential chaos shift keying(DCSK) is a noncoherent scheme with correlation detector. In spite of this there is currently no established procedures attaching importance to the correlation of noises within a code period, which is one of the reasons for the degradation of performance of DCSK system. This paper put forward an improved scheme for noise reduction to DCSK communication system based on its retransmission characteristic. By exploiting the fact that the adjacent noise in the channel is correlated, the proposed scheme adds a phase inversion device at the receiver. The demodulation of improved DCSK scheme is also achieved by a correlation detector. Both the theoretical analysis and the simulation results show that the proposed scheme can greatly improve the BER performance of communication systems, especially for low signal-to-noise ratio (SNR). The proposed scheme can be applied to the systems having a high requirement on data transmission reliability but suffering from hostile communication channels, such as the low-voltage power line(L-PLC) communication systems.