用 ideallp 函数设计 FIR 线性相位滤波器.doc

用 ideallp 函数设计 FIR 线性相位滤波器% G038% 用 ideallp 函数设计 FIR 线性相位滤波器%h_fig1 = figure; % 创建第1个图形窗口set(h_fig1, unit, normalized, position, 0.0, 0.0, 0.99, 0.94);set(h_fig1, defaultuicontrolunits, normalized);set(gcf, color, w)h_text1 = uicontrol(gcf, Style, text, Position, 0.2, 0.9, 0.7, 0.07,. % 在第 1 个图形窗中创建文本框 String, FIR 线性相位滤波器 , FontName, 黑体, ForegroundColor, r, . FontSize, 38, FontWeight, Bold, BackgroundColor, 1, 1, 1); set(gcf, color, w)h_text2 = uicontrol(gcf,style,text, BackgroundColor, w, Position, 0.01, 0.58, 0.2, 0.1,. % 在第 1 个图形窗中创建文本框 string, 滤波器类型, ForegroundColor, r, FontWeight, Bold, FontSize, 20) h_pushbutton1 = uicontrol(h_fig1, Style, PushButton, Position, 0.07, 0.2, 0.08, 0.07,. % 创建命令钮 h_pushbutton2，定义其属性 string, 退出, BackgroundColor, 0.8 0.9 0.8, ForegroundColor, r, FontSize, 14, FontWeight, Bold,. callback, delete(h_fig1)hr_1 = uicontrol(gcf,style,radio, BackgroundColor, w,.% 创建第 1 个 radio 钮 string,低通, ForegroundColor, r, FontWeight, Bold, FontSize, 10,. position,0.04,0.53,0.08,0.05); set(hr_1,value,get(hr_1,Max);set(hr_1, callback, . % 定义第 1 个 radio 钮的回调函数 set(hr_1,value,get(hr_1,max), set(hr_2,value,get(hr_2,min),. set(hr_3,value,get(hr_3,min), set(hr_4,value,get(hr_4,min),. cb05(h_axes1, h_axes2, h_axes3, h_axes4, 1);hr_2 = uicontrol(gcf,style,radio, BackgroundColor, w,.% 创建第 2 个 radio 钮 string,高通, ForegroundColor, r, FontWeight, Bold, FontSize, 10,. position,0.12,0.53,0.08,0.05); set(hr_2,value,get(hr_2,Min); set(hr_2, callback, . % 定义第 2 个 radio 钮的回调函数 set(hr_2,value,get(hr_2,max), set(hr_1,value,get(hr_1,min),. set(hr_3,value,get(hr_3,min), set(hr_4,value,get(hr_4,min),. cb05(h_axes1, h_axes2, h_axes3, h_axes4, 2);hr_3 = uicontrol(gcf,style,radio, BackgroundColor, w,.% 创建第 3 个 radio 钮 string,带通, ForegroundColor, r, FontWeight, Bold, FontSize, 10,. position,0.04,0.45,0.17,0.05); set(hr_3,value,get(hr_3,Min); set(hr_3, callback, . % 定义第 3 个 radio 钮的回调函数 set(hr_3,value,get(hr_3,max), set(hr_1,value,get(hr_1,min),. set(hr_2,value,get(hr_2,min), set(hr_4,value,get(hr_4,min),. cb05(h_axes1, h_axes2, h_axes3, h_axes4, 3);hr_4 = uicontrol(gcf,style,radio, BackgroundColor, w,.% 创建第 4 个 radio 钮 string,带阻, ForegroundColor, r, FontWeight, Bold, FontSize, 10,. position,0.12,0.45,0.08,0.05); set(hr_4,value,get(hr_4,Min); set(hr_4, callback, . % 定义第 4 个 radio 钮的回调函数 set(hr_4,value,get(hr_4,max), set(hr_1,value,get(hr_1,min),. set(hr_2,value,get(hr_2,min), set(hr_3,value,get(hr_3,min),. cb05(h_axes1, h_axes2, h_axes3, h_axes4, 4);h_axes1 = axes(Box, on, Position, 0.27, 0.525, 0.3, 0.3) % 在第 2 个图形窗中创建轴对象h_axes2 = axes(Box, on, Position, 0.65, 0.525, 0.3, 0.3) % 在第 2 个图形窗中创建轴对象h_axes3 = axes(Box, on, Position, 0.27, 0.095, 0.3, 0.3) % 在第 2 个图形窗中创建轴对象h_axes4 = axes(Box, on, Position, 0.65, 0.095, 0.3, 0.3) % 在第 2 个图形窗中创建轴对象% -cb05(h_axes1, h_axes2, h_axes3, h_axes4, 1);function cb05(a1, a2, a3, a4, k)% 计算 Kaiser 窗M = 45; As = 60; n = 0:1:M-1;beta = 0.1102*(As-8.7)+1w_kai = (kaiser(M,beta);% 给定滤波器的参数wc1 = pi/3; wc2 = 2*pi/3;% 根据参数 k，计算滤波器的理想冲激响应if k=1 % 低通 hd = ideallp(wc1,M) end if k=2 % 高通 hd = ideallp(pi,M) - ideallp(wc1,M) end if k=3 % 带通 hd = ideallp(wc2,M)-ideallp(wc1,M);end if k=4 % 带阻 hd = ideallp(wc1,M) + ideallp(pi,M) - ideallp(wc2,M);end% -% 设计低通滤波器h = hd .* w_kai;db,mag,pha,grd,w = myfreqz(h,1);% 画出低通滤波器的特性subplot(a1); stem(n,hd,.); grid; title(（1）理想冲激响应, FontWeight, Bold)xlabel(n, FontSize, 12, FontWeight, Bold); ylabel(hd(n), FontSize, 12, FontWeight, Bold); axis(-1 M -0.5 0.8); set(a1, LineWidth, 2);subplot(a2); stem(n,w_kai,.); grid; title(（2）凯泽窗, FontWeight, Bold)xlabel(n, FontSize, 12, FontWeight, Bold); ylabel(w(n), FontSize, 12, FontWeight, Bold); axis(-1 M 0 1.1); set(a2, LineWidth, 2);subplot(a3); stem(n,h,.); grid; title(（3）实际冲激响应, FontWeight, Bold)xlabel(n, FontSize, 12, FontWeight, Bold); ylabel(h(n), FontSize, 12, FontWeight, Bold)axis(-1 M -0.5 0.8); set(a3, LineWidth, 2);subplot(a4); plot(w/pi,db);xlabel(频率（单位： pi ）, FontSize, 12, FontWeight, Bold); ylabel(分贝数, FontSize, 12, FontWeight, Bold)title(（4）滤波器模频特性, FontSize, 12, FontWeight, Bold); grid;axis(0 1 -110 10); set(a4, LineWidth, 2);set(gca,XTickMode,manual,XTick,0;0.333;0.667;1)set(gca,XTickLabelMode,manual, XTickLabels, 0 ;1/3;2/3; 1 )set(gca,YTickMode,manual,YTick,-60,0)set(gca,YTickLabelMode,manual,YTickLabels,60; 0)function y1=cb06(a1, a2, x, k)Nx=length(x); nx=0:Nx-1;nx1=-Nx:2*Nx-1; x1=x(mod(nx1,Nx)+1);y1,ny1=sigshift(x1,nx1,k); % 2 是移位点数RN=(nx1=0) & (nx1=0) & (ny1Nx);subplot(a1), stem(-6,-5,ny1,3,2,y1,.); xlabel(n, fontsize, 12); ylab