摘要
分析了应答器上行链路信号特点,提出一种自适应解调方法对上行链路信号进行信号解调。采用自适应LMS算法跟踪上行链路信号的频率,计算跟踪误差,并根据跟踪误差进行信号解调。按照欧洲应答器测试规范对其解调性能进行仿真验证,并与过零检测法和非相干解调法进行了比较。仿真结果表明:自适应解调方法在上行链路信号参数存在极端偏移时同样能够满足解调性能要求;当信噪比为7dB时,自适应解调方法的误码率接近0,而过零检测法和非相干解调法的误码率分别为0.163、0.001。自适应解调方法实现简单且具有较强的抗干扰能力,为应答器在电磁环境相对恶劣的场所中可靠应用提供基础。
The characteristic of balise uplink-signal was analyzed. An adaptive demodulation method for balise uplink-signal was introduced. The frequency of uplink-signal was tracked by using adaptive least mean square（LMS） algorithm. The signal was demodulated according to the calculated tracking residual. The demodulation performance was verified according to the Eurobalise test specification and then compared with zero-crossing detection method and non- coherent demodulation method. Simulation result shows that adaptive demodulation method can meet the demodulation performance requirements when there exists extreme migration of uplinksignal. When the signal to noise ratio （SNR） is 7 dB, the error rate of adaptive demodulation method is almost 0, while the error rates of the zero-crossing detection method and the non- coherent demodulation method are 0. 163 and 0. 001 respectively. The adaptive demodulation method is simple to utilize and has strong anti-interference ability. It provides a foundation for the reliable application of balise in comparative harsh electromagnetic environment. 2 tabs, 11 figs, 15 refs.
出处
《交通运输工程学报》
EI
CSCD
北大核心
2013年第6期107-112,118,共7页
Journal of Traffic and Transportation Engineering
基金
铁道部科技研究开发计划项目(2012X004)
