Method for quickly capturing weak signals under high dynamic

The invention discloses a method for quickly capturing weak signals under high dynamic, which comprises the steps of inserting a unique code into a signal frame, and capturing signals by adopting an open-loop algorithm, so that quick capturing can be realized, the channel overhead is low, and the algorithm robustness is good due to independence of other channels. By adopting a self-adaptive judgment threshold, the influence of phase noise caused by low signal-to-noise ratio on a demodulator can be reduced. When large frequency offset exists in received data, the Doppler frequency is divided into a plurality of ranges for parallel frequency offset search, so that the large Doppler frequency change rate can be resisted. 本发明公开了一种高动态下弱信号的快速捕获方法，将独特码插入信号帧中，采用开环算法进行信号捕获，可以实现快速捕获，并且信道开销小，不依赖于其他信道所以算法健壮性好；通过采用自适应判决门限，可以减小噪低信噪比引起的相位噪声对解调器的影响；在接收数据存在大频偏时，通过将多普勒频率划分成多个范围进行并行的频偏搜索，因此能抗大多普勒频率变化率。