基于Duffing振子的低压电力线载波信号检测系统

Low Voltage Power Line Carrier Detection System Based on Duffing Oscillator

针对低压电力线载波通信中各种噪声干扰和信号衰减较强的问题,引入了混沌检测微弱信号理论,利用混沌振子对强噪声背景下特定频率的微弱信号十分敏感的特性,将微弱载波信号作为混沌振子的系统参数,系统参数在临界值附近微小的变化将会引起系统状态的改变,根据状态改变所需条件估计出微弱载波信号的参数。依据此原理,通过对Duffing振子(一种混沌振子系统)的系统参数进行定量分析,建立基于Duffing振子的低压电力线QPSK(正交相移键控)载波信号检测系统,并通过在低压电力线传输模型上对该检测系统进行测试,实验表明,在低压电力线噪声环境下该检测系统能够准确检测15m V以上的QPSK载波信号的相位分量,而且能有效地抵抗背景噪声干扰,并对典型的持续时间在120μs以下的脉冲噪声也有很好的抑制作用,大大降低了数据传输中因脉冲噪声引起的比特(位)错误和突发错误。

Chaos detection weak signal theory is presented for the problem of various noise interference and signal strong attenuation in low voltage power line carrier communication,the characteristic that Chaos oscillator is very sensitive to weak signal of specific frequency in strong noise environment is used to take weak carrier signal as a system parameter,the system＇s state changes if the system parameter has a slight change near the threshold. The carrier signal parameter is estimated according to the necessary condition for state change. According to this principle,low voltage power line QPSK carrier detection system based on Duffing oscillator is established by analyzing Duffing oscillator parameter（ a kind of chaos system）. This detection system is tested in low voltage power line model,results show that this detection system can detect phase component of QPSK signal whose amplitude is over15 m V in low voltage power line noise environment,stand effectively against background noise,restrain impulse noise whose width is less than 120 μs,reduce bit error and burst error caused by impulse noise in data transmission.