长电缆传输中的变步长自适应噪声对消算法

Adaptive Noise Cancellation Algorithm with Variable Step Size in Long Cable Transmission

数字信号在长电缆中传输时,电缆芯线之间会存在串扰,电缆上会存在回波以及噪声干扰,严重的时候传输信号能量和噪声能量在一个数量级上,导致信号传输时的误码率增加。为了降低传输误码率,文中提出了一种新的变步长自适应噪声对消算法,算法迭代的过程中采用误差信号的瞬时能量和输入信号能量的比率作为自适应噪声对消算法的自适应反馈量,并通过比率的加权均值来控制步长的更新,从而消除噪声和回波对算法迭代过程的累积影响。仿真和实验结果表明,在低信噪比的传输环境中,改进算法仍然具有较快的收敛速度和较小的稳态误差,使得数据通信能够保持较高的通信速率。

In the process of digital signal transmission on long cable,there is a crosstalk between different core lines and there are echoes and noise jamming on the cable,in the serious time,the energy of the signal and the noise energy are in an order of magnitude,which increase the error rate of signal transmission. In order to reduce the transmission error rate,this paper proposed a new variable step size adaptive noise cancellation algorithm. In the process of iterative algorithm,the ratio of the error signal and the input signal of the instantaneous energy were as the adaptive feedback of the adaptive noise cancellation algorithm,and the weighted mean value of the ratio was used to control the step size update,so as to eliminate the cumulative influence of noise and echo. The simulation and experimental results show that in low SNR environments,the improved algorithm still has fast convergence speed and small steady-state error,so that the data communication can keep high communication rate.