Aiming at the problem in the radio Doppler amplitude comparison system,namely the lack of effects of troditional mathods or wavelet soft and hard threshold filter may affect orientation judgment,we proposed a threshold function on the basis of wavelet transform.In order to retain its original part on the signal and extent to filter most of the noise,the threshold function had shrinkage treatment on the smaller shrinkage coefficients when it handled with system signal,which overcome the problems of hard and soft threshold filter.The simula-tion and verification results showed that the signal handled with our function had better noise-signal ratio and mean square deviation compared with the other mathods when the noise intensity is between-8 dB to 8 dB in the process of Doppler detection signal denoising.%针对无线电多通道振幅比较系统中，传统滤波方法及基于小波的软硬阈值函数去噪效果不佳可能影响系统判断能力的问题，提出了基于小波变换的改进去噪阈值函数。该阈值函数处理小波系数时，为了保留其上的真实信号的同时又最大程度的滤去噪声，对较小的小波系数进行收缩处理，在一定程度上克服了硬阈值函数估计值重构的信号产生震荡及软阈值函数重构信号与真实信号逼近程度不足的缺点。仿真验证表明，在对多普勒检波信号的去噪过程中，噪声处于-8~8 dB 区间时，经过该函数处理后得到的信号信噪比和均方差效果优于进行比较的其他函数。
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