Abstract：The present inbound demodulation in two way power frequency automatic communication system(TWACS)is implemented with the voltage zero-crossing signals as the benchmark, and the voltage phase difference of transceiver can cause the deviation in receiving time-domain and influence the communication performance seriously, and cannot take upload alarm information limited by master-slave mode. In this connection, this paper proposes a new method, which added preface information based on pseudorandom sequence in inbound modulation, and the receiver will change the preface information into composite signal according to the coding. Due to the modulation components of the composite signal being improved, and the precise demodulation time-domain can be found through wigner distribution for time-frequency analysis, which makes the inbound demodulation adapt the voltage phase difference of transceiver, and thereby enhances the communication performance. Meanwhile, inbound demodulation based on active mode can be conducted by using the autocorrelation of pseudorandom sequence, thus realize the real-time alarm functions. The demodulation performance in this design has confirmated by field scale applications.
卢文冰, 孙凤杰, 罗应立. 工频通信系统上行信号对电压相位差的自适应解调[J]. 电工技术学报, 2013, 28(1增): 251-258.
Lu Wenbing, Sun Fengjie, Luo Yingli. Self-Adaption Demodulation for Voltage Phase Difference of Inbound Signals in TWACS. Transactions of China Electrotechnical Society, 2013, 28(1增): 251-258.
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2013, Vol. 28 
