关键词: 混沌通信, 差分混沌移位键控, 反相, 低压电力线通信

Abstract: In order to reduce the side effects of noise correlation on DCSK system，the reversed-phase overlay demodulation scheme is put forward in this paper based on the retransmission characteristic of DCSK.In the first scheme，the first and the second half-symbol signals within a code period are reversed-phase overlapped firstly.Then the variable for judgments is gotten from the related operations results of the overlaid signal with the first half-symbol signal.In the second scheme，the judgment variable is gotten by subtracting the related operation results of the first and the second half-symbol signals from the judgment variable of the first scheme.As long as the noises within the first and the second half-symbol have the positive correlation characteristic，the proposed schemes can effectively suppress noise impact than the existing scheme whose judgments variable is directly calculated by the correlation of the first and the second half-symbol of received signals.Besides，the noise tolerance is further improved in the second scheme when the noise correlation coefficient is less than 0.5.

Key words: chaos communication, Differential Chaos Shift Keying（DCSK）, phase inversion, Low-vlotage Power Line Communication（L-PLC）