摘要
再入遥测信道是遥测过程中的一种特殊信道情况,当飞行器通过再入遥测信道时,黑障和多径效应会造成脉冲编码调制/调频(pulse code modulation/froquence modulation,PCM/FM)遥测信号信噪比降低和频率选择性衰落,甚至突破传统解调方法的解调门限,导致误码率大大增加。针对该问题,研究一种滑动长度为1的多符号检测(multi-symbol detection,MSD)解调算法:对连续观测到的N个码元信号与本地信号进行联合检测,但每次MSD判决较前一次MSD判决有N-1个码元的重合。理论上该算法可以将信道增益提高3 dB左右,仿真和测试结果验证了该算法的有效性。
Reentry telemetry channel is a special channel in the process of remote sensing, when aircraft through the reentry telemetry channel, black barrier and multipath effect will cause the PCM/FM telemetry signal to noise ratio and frequency selective fading, even break through the demodulation threshold of traditional demodula- tion method, which led to the bit error rate is greatly increased. In view of this problem, a MSD （ Multi - Symbol Detection） demodulation algorithm with sliding length of 1 is researched ： Continuous observations of N element sig- nal and local signal for joint detection, but each time the MSD sentences a MSD earlier with N - 1 element coinci- dence. In theory, the algor/thm can increase the channel gain about 3 dB. Simulation and test results verify the ef- fectiveness of the proposed algorithm.
出处
《科学技术与工程》
北大核心
2014年第8期274-277,共4页
Science Technology and Engineering
