基于自适应分解级数小波去噪的TDOA估计算法研究  

Research on TDOA Estimation Algorithm Based on Adaptive Decomposition Level Wavelet Denoising

作　　者：张羽博 ZHANG Yubo(Wuwei Monitoring Station of Gansu Radio Monitoring Station,Wuwei 733000,China)

机构地区：[1]甘肃省无线电监测站武威监测站,甘肃武威733000

出　　处：《无线电工程》2023年第1期114-121,共8页Radio Engineering

摘　　要：在无源时差(Time Difference of Arrival, TDOA)定位技术中,针对现有基于广义互相关时差估计方法对目标信号波形相关度要求高、信号受噪声干扰严重时其时差估计精度难以满足实际需求等问题,提出一种具有自适应分解级数的小波去噪预处理时差估计方法。对待处理信号进行多级小波分解,计算分解后各级系数向量的能量贡献率累加和(Energy Contribution Rate Cumulative sum, ECRCs),以满足ECRCs不小于80%的最小分解级数作为小波去噪的分级参数。结合计算的自适应分解级数及小波去噪方法对待处理信号进行自适应去噪处理,结合广义互相关算法对处理后信号进行峰值分析,得到两信号的时差值。通过仿真信号及甘肃某地实测的TDOA数据进行分析验证,结果表明,所提方法可有效提升时差估计精度及稳定性,尤其信号受噪声干扰较大时具有一定优势。In the application of Time Difference of Arrival(TDOA) technology, to solve the problems that the existing general TDOA estimation methods based on cross-correlation, which require high correlation of the received signal waveform and the estimation accuracy is difficult to meet the actual requirements when the signal is seriously disturbed by noise, a wavelet denoising preprocessing TDOA estimation method with adaptive decomposition level is proposed. Firstly, the signal to be processed is decomposed by multi-level wavelet, and the Energy Contribution Rate Cumulative sum(ECRCs) of each level coefficient vector is calculated. The minimum classification number of which ECRCs is not less than 80% is selected as the decomposition level of wavelet denoising. Then, combined with the calculated adaptive decomposition layer and wavelet denoising method, the signal to be processed is denoised adaptively. Finally, the peak value of the processed signal is analyzed combined with general cross correlation algorithm to obtain the time difference of the two signals. Through the analysis and verification of the simulation signal and the measured TDOA data in a place in Gansu, the results show that the proposed method can effectively improve the accuracy and stability of TDOA estimation, especially when the signal is greatly disturbed by noise.

关 键 词：TDOA 时差估计 自适应分解级数 小波去噪 抗噪能力 

分 类 号：TN98[电子电信—信息与通信工程]