实现一个数字信号处理的仿真系统 。要求具有界面并实现以下功能：

1）能产生（得到）并选择各种数字信号（sin、方波、三角波、语音、噪声及其叠加）；

2）具有DFT、DCT和小波变换和经典功率谱估计功能；

3）具有设计IIR和FIR低通、高通、带通滤波器功能；

4）能显示时域和频域波形，演示输入信号经过系统得到输出信号过程及频域特性和时间序列。

-Implement a simulation system of digital signal processing. It requires interface and implements the following functions: 1) to produce (get) and　various digital signals (sin, square, triangle, voice, and noise superposition)　2) having DFT, DCT and wavelet transform and classic power spectrum estimation function　3) with the design IIR and FIR low pass, high pass, band-pass filter function　4) time domain and frequency domain waveforms, Demos input signal an output signal through the system and the process of frequency-domain and time-series properties can be displayed.