极低信噪比下的信号同步捕获技术研究

摘要

Based on the idea of time-domain partial correlation frequency domain search synchronization algorithm, a technical scheme for signal synchronous capture at very low SNR is proposed in the paper. The special repetitious synchronization preamble is designed and the partially-matched filter FFT technology is used to implement the signal synchronous capture at very low SNR and large freguency offsetting. Simulation indicates that with this scheme, the synchronous capture probability of above 98%can be achieved when the SNR of AWGN is at-29 dB. The computing complexity is fairly reduced with proper processing technology in this scheme.And thus the proposed scheme is implemented on TI6713DSP.%采用时域部分相关频域搜索同步算法思想，提出一种极低信噪比条件下实现信号同步捕获的技术方案。该方案设计了特殊的重复同步头信号，采用部分匹配滤波快速傅里叶技术，实现了极低信噪比、大频偏条件下的信号同步捕获。仿真结果表明：在信噪比为-29 dB的加性高斯白噪声信道条件下，该方案的同步捕获概率达到98％以上。此外，该方案采用合适同步处理方法降低了算法运算量，完成了在TI-6713DSP平台的工程实现。