提出一种波束域MUSIC时延测量法,该方法对参考信号与接收信号的互相关函数做离散傅里叶反变换,然后对反变换序列做重构处理,将多径信号到达时延测量问题转换成谱估计问题.算法根据时延的时间分布形成波束转换矩阵,让形成波束的主瓣覆盖时延所在的时间区域,然后再用MUSIC算法做时延测量.理论分析和仿真结果表明,与传统的MUSIC时延测量算法相比,新方法计算量更小,信噪比时延分辨率门限更低.
A beam space multiple-signal-classification (MUSIC) method of time difference measurement is proposed. In our method, the time difference measurement is first transformed into the frequency domain, in which the problem is converted into spatial spectrum estimation by computing the inverse discrete fourier transform (IDFT) of the cross-correlation function for sent signal and received signal. Next, the time difference distribution are estimated by beam-forming system, then formed the beams and let their main lobes covered the time spaces which contain the time difference of multipath signals. Then, a MUSIC algorithm is applied to achieve the time difference of each mulfipath signals. Both theory analysis and simulation show computational complexity of the new method is reduced and lower signal-to-noise ratio for resolution is needed comparing to the MUSIC algorithm applied to time difference measurement.