低轨道卫星隐蔽通信快速捕获技术研究

针对低轨道卫星隐蔽通信系统特有的接收机低信噪比、超大多普勒频偏及快速捕获要求等特点,提出一种时间频率二维准全并行多符号累积捕获实现算法,并对算法中关键参数进行优化设计.载荷样机测试结果表明,该算法在符号速率为1ksample/s,多普勒频偏为±50kHz,接收机信噪比Es/N0最小为3dB条件下,捕获时间优于100ms,漏检概率小于0.003,虚警概率小于3×10-6.

Fast Capture Technique for Concealing Communication of Low Earth Orbit Satellite

Low-orbit satellite communication system has the features of low SNR receiver, large Doppler shift and fast capture requirement. To meet those demands in concealing communication, this article presents a time-frequency two-dimensional quasi-parallel multi-symbol cumulative capture algorithm. The critical parameters of the algorithm have been designed and optimized. The loaded prototype and signal processing platform have been built to test the performance of the designed algorithm. The test results show that all the indexes meet the project requirements. Under the conditions of that the symbol rate is 1 ksample/s, Doppler frequency shift is ±50 kHz and the receiver E_s/N₀ is no more than 3 dB, the capture time is less than 100 ms and the probability of missed detection is less than 0.003.