数字信号实验一序列的产生.doc

实验一 序列的产生及绘图 一、实验目的1熟悉信号处理软件MATLAB的使用。2离散信号的基本运算实现。3了解基本序列及复杂序列的产生方法。4运用卷积方法观察系统的时域特性。5掌握线性时不变系统的频域表示方法。二、实验内容 1熟悉扩展函数 2运行例题程序 3编程实现下列内容（1）利用扩展函数产生序列并画图 (a) -5=n=5(b) 和 0=n=50 w(n)为白噪声 函数为 w=randn(size(n)（2）设线性移不变系统的抽样响应为 输入序列为 求系统输出 y(n)并画图 二、实验步骤例2 产生序列并画图 0=n=20实验结果：x = Columns 1 through 9 0 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 Columns 10 through 18 9.0000 10.0000 7.4082 5.4881 4.0657 3.0119 2.2313 1.6530 1.2246 Columns 19 through 21 0.9072 0.6721 0 例3 产生复信号 -10=n=10并画出复序列的实部、虚部、幅值和相位离散图实验结果：x = Columns 1 through 5 -2.6911 - 0.3836i -2.2237 - 1.0512i -1.6411 - 1.5033i -1.0166 - 1.7383i -0.4140 - 1.7745i Columns 6 through 10 0.1166 - 1.6446i 0.5406 - 1.3904i 0.8391 - 1.0574i 1.0081 - 0.6897i 1.0558 - 0.3266i Columns 11 through 15 1.0000 0.8644 + 0.2674i 0.6757 + 0.4623i 0.4605 + 0.5803i 0.2429 + 0.6248i Columns 16 through 20 0.0429 + 0.6050i -0.1247 + 0.5345i -0.2507 + 0.4287i -0.3313 + 0.3035i -0.3676 + 0.1738i Column 21 -0.3642 + 0.0519i作业：利用扩展函数产生序列并画图(1) -5=n=5程序：n=-5:5;x=2*impseq(-2,-5,5)-impseq(4,-5,5);subplot(2,1,1);stem(n,x);xlabel(n);ylabel(x(n);axis(-5,5,-3,3);结果：x = 0 0 0 2 0 0 0 0 0 -1 0(2) 0=n=50 程序：n=0:50;x=cos(0.04*pi*n)subplot(2,1,1);stem(n,x);xlabel(n);ylabel(x(n);axis(0,50,-2,2);结果：x = Columns 1 through 9 1.0000 0.9921 0.9686 0.9298 0.8763 0.8090 0.7290 0.6374 0.5358 Columns 10 through 18 0.4258 0.3090 0.1874 0.0628 -0.0628 -0.1874 -0.3090 -0.4258 -0.5358 Columns 19 through 27 -0.6374 -0.7290 -0.8090 -0.8763 -0.9298 -0.9686 -0.9921 -1.0000 -0.9921 Columns 28 through 36 -0.9686 -0.9298 -0.8763 -0.8090 -0.7290 -0.6374 -0.5358 -0.4258 -0.3090 Columns 37 through 45 -0.1874 -0.0628 0.0628 0.1874 0.3090 0.4258 0.5358 0.6374 0.7290 Columns 46 through 51 0.8090 0.8763 0.9298 0.9686 0.9921 1.0000(3) 0=n=50 w(n)为白噪声 函数为 w=randn(size(n)程序：n=0:50;x1=cos(0.04*pi*n);x2=0.2*randn(size(n);x=x1+x2;subplot(2,1,1);stem(n,x);xlabel(n);ylabel(y(n);axis(0,50,-2,2);结果：x = Columns 1 through 8 0.8809 0.9622 0.8816 0.9139 1.1833 0.6877 0.4595 0.7313 Columns 9 through 16 0.3551 0.4330 0.1835 0.2945 0.1734 -0.1035 -0.5982 -0.2825 Columns 17 through 24 -0.1072 -0.3321 -0.9535 -0.7447 -0.9453 -1.0812 -1.1766 -0.9108 Columns 25 through 32 -1.0780 -0.9888 -1.0657 -1.0616 -0.8556 -0.7307 -0.3866 -1.0004 Columns 33 through 40 -0.8419 -0.3283 -0.5037 -0.5853 -0.1243 0.2479 0.2044 0.578