低信噪比下频率编码信号参数估计

针对低信噪比条件下，频率编码信号的瞬时频率估计容易受噪声影响的问题，提出了将自适应阈值消噪技术与小波变换结合起来的新方法。首先利用连续小波变换计算信号的小波谱，然后对小波谱进行自适应阈值消噪处理，进而提取小波谱脊线，得到频率编码信号的脉内调制信息。计算机仿真结果验证了该方法的可行性。

A New Method of Extracting In-Pulse Characteristics from FSK Signal in Low SNR

In low SNR, the frequency estimation of FSK signal is susceptible to noise. In this paper, we propose a new method, which combines wavelet transform technique and adaptive threshold denoising technique. Firstly, gain the wavelet spectrum of the signals by computing continuum wavelet transform, then restrain noise by adaptive threshold. Finally, get the in-pulse characteristics of FSK signal by extracting the ridge of the spectrum. Simulations verify the feasibility of the method.