面向窄带通信信号的相位谱时差估计方法研究

Research on TDOA Estimation Method Based on Phase Spectrum for Narrow-Band Communication Signal

对窄带通信信号采用相位谱法进行时差估计,由于信号能量谱非平坦,会出现相位解绕效果较差的现象,对此本文提出一种改进的加权最小二乘拟合方法,以更加合理地利用解绕后的相位数据,从而提高相位谱法时差估计精度。同时结合改进的最大似然相位谱法,本文还设计一种简单实用的面向窄带通信信号时差估计的频域数据压缩方法,以求在时差估计精度和数据传输量之间获取较好平衡。经仿真验证,改进的相位谱时差估计方法较大程度地提高了窄带通信信号的时差估计精度,同时,基于改进相位谱法的数据压缩可以实现用时差估计精度的适度降低换取数据传输量的大幅度减少,具有在资源有限的传感网等场合的良好应用前景。

When phase spectrum method was applied in TDOA （Time Difference of Arrival） estimation for narrow- band communication signal, the effect of phase unwrapping was bad as signal＇ s power spectrum was non-fiat, Aiming at this phenomenon, this paper proposed a modified weighted least squared fitting method that utilizing these unwrapped phase data more reasonably, to improve the accuracy of TDOA estimation based on phase spectrum method. And, com- bined with the modified maximum likelihood phase spectrum method, this paper also designed a simple and practical data compression method in frequency domain for TDOA estimation of narrow-band communication signal, to balance he data amount for transmission and the accuracy of TDOA estimation well. Simulations prove that, the modified phase spectrum method can improve the accuracy of TDOA estimation for narrow-band communication signal obviously, and after data compression by proposed method under certain large compression ratio, good enough TDOA estimation results can be still acquired, so the proposed data compression method has good application future in resource-constrained field like sensors network.