基于HHT的三维频谱分析仪的FPGA实现

Spectrum analyzer is one of the essential tools in Digital Signal Processing, but most of the traditional spectrum analyzers are based on Fast Fourier Transform (FFT), which only can analyze the global energy-frequency distributions mainly for linear and stationary signal but is hard to display the trend of instantaneous frequency and energy. To solve this problem, the paper designs a 3D Spectrum analyzer with the FPGA chip and NIOS II processor of Altera. In the proposed system, the real-time signal is collected through audio acquisition module on DE2 and Hilbert-Huang Transform (HHT) module is designed to process the signal. Moreover, the analysis results in terms of the graph of time, the frequency and energy distribution are displayed by the VGA module. Experiment results show that our spectrum analyzer is very suitable for nonlinear and non-stationary signal, which is able to show the instantaneous frequency and energy of the signal very clearly, and overcomes the drawbacks of the traditional signal analyzers.