Experiment 3 uses the fast convolution method to filter the previously generated mixed noise audio signal
Requirements: Select the audio signal in sub-task 1, give the unit sampling response of the filter by yourself, use fast convolution to filter the audio signal, and compare the waveform of the signal before and after filtering and the effect of playback.
The final overall effect is as follows:
1. The principle of fast convolution
Fast convolution mainly has two modes: FFT convolution and block convolution. The FFT convolution form is discussed below.
Let the voice signal be x(n), and the unit sample be correspondingly h(n). Convolution in the time domain is the product in the frequency domain. Therefore, according to this principle, x(n)and h(n)respectively obtained through the fast Fourier transform FFT to obtain the frequency domain signals H ( ω ) and X ( ω ) H(\omega) and X( \omega)