基于DSP的BOC信号捕获算法实现

针对BOC调制信号自相关函数多峰值造成的捕获模糊性问题,提出一种基于相关函数的去模糊性捕获算法。该算法能消除接收信号载频的影响；根据BOC伪码的相关函数计算原理构造与收信号相关的两路本地信号；根据相关结果的对称性,通过简单数学运算组成一个完全无模糊性的相关函数。理论分析和仿真结果表明,相比ASPeCT算法及重构相关算法,提出的捕获算法的主峰均值比例更高,副峰均值比例更低。在两径信道中,当时延小于一个码片时,该算法的主峰能量可达100%。利用TMS320C5509A芯片进行算法验证,进一步验证了该算法的有效性。

Implementation of BOC Signal Acquisition Algorithm Based on DSP

Aiming at the ambiguity in acquisition of the BOC modulation signal, which is caused by the multi-peaks of auto-correlation function, an acquisition algorithm was proposed on the basis of composition principle and unique characteristics of auto-correlation function. Firstly, the effect of signal carrier frequency was eliminated. Then according to the correlation function calculation principle of BOC pseudo-code, two local signals were constructed to correlate with received signal. Finally, a new correlation function without sub-peaks was formed through simple mathematical operation by utilizing the symmetry of the correlation results. Theoretical analysis and simulation results showed that the new algorithm had higher main peak proportion, lower sub-peak proportion than ASPeCT algorithm and fractal-reconstruction algorithm. In the two_ray channel, its main peak power reached to 100% in less than one chip of delay. Furthermore, TMS320C5509A chip was used to verify the algorithm, which further showed the effectiveness of the algorithm.