低信噪比条件下BOC信号的快捕算法研究

针对全球导航卫星系统中的二进制偏置载波(BOC),介绍了其生成原理,分析了其自相关函数的特点.研究了常用的BPSK-L IKE单边带和双边带捕获算法及其优缺点,结合基于快速傅立叶变换(FFT)的码并行处理结构,利用BOC信号自相关函数以及BOC信号和伪随机噪声码(PRN)序列的互相关函数两者的差值作为捕获算法的输出,给出了一种可以消除自相关函数的边峰带来的模糊性的捕获算法.仿真结果表明:该算法无能量损失,可接受的最低信噪比低于其它算法2 dB,且其复杂度低.

Research of Fast Acquisition Algorithms for BOC Signals Under Lower SNR

The principle of the binary offset carrier(BOC) modulation in GNSS is introduced and its autocorrelation function is analyzed.The common binary phase shift key(BPSK)-LIKE single/double bands acquisition algorithms and also their merits and demerits are studied.Combined with fast Fourier transform(FFT) based code parallel processing architecture,the difference between BOC autocorrelation function and the cross-correlation function of BOC and pseudo-random noise(PRN) is applied as the output of acquisition algorithm.The algorithm which can restrain the ambiguity resulted from the BOC autocorrelation function is given.The simulation results show that,the given algorithm has no energy loss and less computation complexity,and its acceptable minimum signal noise ratio(SNR) is 2 dB smaller than that of other algorithms.