电气化铁路信号传输中的自适应干扰对消器的研究

Study and Application of Adaptive Interference Canceller for Signal Transmission Systems Used in Electrified Railway

随着铁路运输现代化 ,信号信息传递的可靠性问题显得日益突出 ,尤其在电气化区段信号信息传送受到干扰的问题更加严重。针对这个问题 ,本文设计与试验了自适应干扰对消系统 ,采用该方案基于以下理由 ,其一 ,地面与机车信息传输量日益增大 ;其二 ,牵引电流的频率、幅度是不断变化的 ,而且其模型易于提取。文中结合电力干扰实际情况 ,从理论上推导出自适应对消算法 ,并进行计算机模拟 ,模拟结果表明 ,信噪比可提高 2 0dB～ 30dB。此外 ,还进行了硬件实现 ,并给出采用回波消除器MT912 2的实现方案 ,以改进处理效果。实验结果表明 ,信噪比有较大改善 ,与计算机模拟结果相近。

With the modernization of railway transportation, reliability of the signal transmission has been focused. Interference on signal message transmission in the electrified section is getting serious. To solve the problem, we have designed and tested the adaptive interference canceller for signal transmission systems used for electrified railway. There are two reasons to adopt the above solution: (1) The message transmission volume between the wayside and cab is increasing. (2) The frequency and amplitude of the traction current keep change continuously, and it is easy to pick-up the model. In this paper, adaptive canceller algorithm has been derived in theory and the computer simulation for this algorithm has been accomplished. The simulation results have shown that S/N ratio can be improved by 20 dB-30 dB. In addition, the solution has been put into effect through hard ware and gives the realization solution by using echo canceller MT9122. Our experimental results show that S/N ratio improvement has approached the results obtained in the computer simulation.