应用欠采样技术的多正弦波频率估计方法研究

Research on multiple frequencies estimation of sinusoidal signals with application of sub-Nyquist sampling technique

为了解决高频段信号由于受到A/D转换器和后续信号处理器件运算速度和成本的限制,提出一种用欠采样获得Nyquist采样的信号处理方法。将信号分成两路进行欠采样,根据两路信号构造一个新信号,得到一个虚拟的Nyquist采样值,进行傅里叶变换,单信号时直接得到所估计信号的频率值;多信号情况下在得到各信号频率估计值的同时,会得到因频率"交叉"引起的虚假频率点,通过对双路傅氏变换的结果进行处理可以消除虚假频率点。仿真实验验证了该方法的有效性。

To solve the problem of low computation speed and high cost caused by A/D converter and latter processors in high-frequency section, a novel method for multiple frequencies estimation of high-frequency sinusoidal signals based on sub-Nyquist is proposed. Signals are divided into two channels, which are sampled in sub-Nyquist frequency respectively. A new signal is constructed through the two channel signals to obtain a dummy Nyquist value. Fourier transformation is used to obtain the frequency estimation. The frequency can be obtained directly when there is only one signal. Under the circumstance of multi- ple signals, the two channels FT results are applied to eliminating the false frequency caused by frequency crossing. Simulation results verify the effectiveness of the proposed algorithm.