基于二次互相关的时延估计算法改进

The Improved Time-Delay Estimation Method Based on the Quadratic Correlation Function

摘要: 广义互相关时延估计和广义二次互相关时延估计验证了不同的权函数会对估计精度有不同的影响。通过对比不同权函数的优缺点，从理论上改进了加权的窗函数，该窗函数对二次互相关重新进行加权，从而提高了小功率信号在低信噪比条件下的时延估计精度。在相同的环境下，仿真对比了传统的权值和改进的权值在时延估计中的峰值。通过不同的环境噪声仿真得出不同的结果，对比仿真的结果表明，与其他权值相比较，改进后的权值使得小功率信号在低信噪比情况下能够取得较高的时延估计精度。

Abstract: Generalized correlation of TDE and the second correlation of TDE verify that different weight functions will have different effects on accuracy of estimation. After comparing the advantages and disadvantages of different weight function, this paper improves the method of weighting theoretically. This method re-weights the second correlation and improves the accuracy of esti-mation of TDE in the condition of lower SNR accordingly. This paper contrasts the peak of traditional weight in TDE with the improved weight under the same condition of noise. Simulation results show that the improved weights can achieve higher accuracy of estimation under the condition of the low-power signals in the lower SNR compared with other weights.