Matlab【信号处理】基于窗函数实现数字信号频谱分析附matlab代码.zip

%% 声音的采集 clc; clear; close all; filename = '三狮.wav'; [y,Fs] = audioread(filename); y = y(:,1); % 取单声道 L = length(y); % 采样点 T = 1/Fs; % 周期 t = (0:L-1)*T; info = audioinfo(filename); % wav详细信息 disp(info); % 输出音频信号 采样频率，采样位数 等信息 sound(y,Fs); %以采样率 Fs 向扬声器发送音频信号 y i = 0; %% 绘图 i = i+1; s = '原音频信号时域波形图'; plot_time(t,y,s,i); % 绘制时域波形图 i = i+1; s = '原音频信号频域波形图'; plot_freq(Fs,L,y,s,i); % 绘制频域波形图 %% 窗函数对频谱分析的影响 %% 矩形窗 win_r = boxcar(length(y)); y_win_r = y.*win_r; % 时域乘积 sound(y_win_r,Fs); i = i+1; s = '矩形窗时域波形图'; plot_time(t,y_win_r,s,i); i = i+1; s = '矩形窗频率域波形图'; plot_freq(Fs,L,y_win_r,s,i); % 矩形窗 1/2 win_r_2 = boxcar(floor(length(y)/2)); % 取语音长度1/2为窗口长度 win_r_2 = [win_r_2;zeros(ceil(length(y)/2),1)]; % 对齐补0 y_win_r_w = y.*win_r_2; sound(y_win_r_w,Fs); i = i+1; s = '矩形窗(N = L/2)时域波形图'; plot_time(t,y_win_r_w,s,i); i = i+1; s = '矩形窗(N = L/2)频率域波形图'; plot_freq(Fs,L,y_win_r_w,s,i); %% 汉宁窗 win_h = hann(length(y)); y_win_h = y.*win_h; sound(y_win_h,Fs); i = i+1; s = '汉宁窗时域波形图'; plot_time(t,y_win_h,s,i); i = i+1; s = '汉宁窗频率域波形图'; plot_freq(Fs,L,y_win_h,s,i); % 汉宁窗 1/2 win_h_2 = hann(floor(length(y)/2)); win_h_2 = [win_h_2;zeros(ceil(length(y)/2),1)]; % 对齐补0 y_win_h_2 = y.*win_h_2; sound(y_win_h_2,Fs); i = i+1; s = '汉宁窗(N = L/2)时域波形图'; plot_time(t,y_win_h_2,s,i); i = i+1; s = '汉宁窗(N = L/2)频率域波形图'; plot_freq(Fs,L,y_win_h_2,s,i); %% 哈明窗 win_hm = hamming(length(y)); y_win_hm = y.*win_hm; sound(y_win_hm,Fs); i = i+1; s = '哈明窗时域波形图'; plot_time(t,y_win_hm,s,i); i = i+1; s = '哈明窗频率域波形图'; plot_freq(Fs,L,y_win_hm,s,i); % 哈明窗 1/2 win_hm_2 = hamming(floor(length(y)/2)); win_hm_2 = [win_hm_2;zeros(ceil(length(y)/2),1)]; % 对齐补0 y_win_hm_2 = y.*win_hm_2; sound(y_win_hm_2,Fs); i = i+1; s = '哈明窗(N = L/2)时域波形图'; plot_time(t,y_win_hm_2,s,i); i = i+1; s = '哈明窗(N = L/2)频率域波形图'; plot_freq(Fs,L,y_win_hm_2,s,i); %% 布莱克曼窗 win_blk = blackman(length(y)); y_win_blk = y.*win_blk; sound(y_win_blk,Fs); i = i+1; s = '布莱克曼窗时域波形图'; plot_time(t,y_win_blk,s,i); i = i+1; s = '布莱克曼窗频率域波形图'; plot_freq(Fs,L,y_win_blk,s,i); % 布莱克曼窗 1/2 win_blk_2 = blackman(floor(length(y)/2)); win_blk_2 = [win_blk_2;zeros(ceil(length(y)/2),1)]; % 对齐补0 y_win_blk_2 = y.*win_blk_2; sound(y_win_blk_2,Fs); i = i+1; s = '布莱克曼窗(N = L/2)时域波形图'; plot_time(t,y_win_blk_2,s,i); i = i+1; s = '布莱克曼窗(N = L/2)频率域波形图'; plot_freq(Fs,L,y_win_blk_2,s,i); %% 截取2s time = 2; samples = [1,floor(L/2)]; [y_cut,Fs_cut] = audioread(filename,samples); y_cut = y_cut(:,1); % 取单声道 L_cut = length(y_cut); % 采样点 T_cut = 1/Fs_cut; % 周期 t_cut = (0:L_cut-1)*T_cut; sound(y_cut,Fs_cut); i = i+1; s = '音频信号截取2s时域波形图'; plot_time(t_cut,y_cut,s,i); % 绘制时域波形图 i = i+1; s = '音频信号截取2s频域波形图'; plot_freq(Fs_cut,L_cut,y_cut,s,i); % 绘制频域波形图 %% 降采样对频谱分析的影响 Fs_res = Fs/2; y_res=resample(y,Fs_res,Fs);%信号降采样处理 % y_res = downsample(y,2); L_res = length(y_res); sound(y_res,Fs_res); t_res = 1/(Fs_res) * (0:L_res-1); i = i+1; s = '降采样时域波形图'; plot_time(t_res,y_res,s,i); i = i+1; s = '降采样频率域波形图'; plot_freq(Fs_res,L_res,y_res,s,i);