数字信号处理Matlab练习.docx

1、数字信号处理Matlab练习数字信号处理Matlab练习第1章1、序列xn、yn、znxn=3 -2 0 1 4 5 2,yn=0 7 1 -3 4 9 -2,wn=-5 4 3 6 -5 0 1,（1）xn序列（2）yn序列 （3）wn序列 2.求序列xn= 3 -2 0 1 4 5 2的自相关序列 x=3 -2 0 1 4 5 2x = 3 -2 0 1 4 5 2 y=3 -2 0 1 4 5 2y = 3 -2 0 1 4 5 2 n1 = length(y)-1; n2 = length(x)-1;r = conv(x,fliplr(y); 计算两矩阵的卷积k = (-n1):n2;

2、 定义时间变量stem(k,r); 绘制二维离散时间信号xlabel(Lag index); ylabel(Amplitude);v = axis;axis(-n1 n2 v(3:end); 矩阵计算范围 m=xcorr(x,y) 求两矩阵互相关系数3.求序列yn= 0 7 1 -3 4 9 -2的自相关序列(方法同上)4.求序列wn=-5 4 3 6 -5 0 1的自相关序列（方法同上）5.求序列xn与yn的互相关序列 x=3 -2 0 1 4 5 2x = 3 -2 0 1 4 5 2 y=0 7 1 -3 4 9 -2y = 0 7 1 -3 4 9 -2m = Columns 1 th

3、rough 7 -6.0000 31.0000 -6.0000 -19.0000 10.0000 49.0000 40.0000 Columns 8 through 13 27.0000 4.0000 27.0000 37.0000 14.0000 0.00006.求序列xn与wn的互相关序列m = Columns 1 through 7 3.0000 -2.0000 -15.0000 29.0000 1.0000 6.0000 -35.0000 Columns 8 through 13 12.0000 36.0000 38.0000 6.0000 -17.0000 -10.00007.画出序

4、列x1n和x2n，序列的序号n和参数M自己选择(a) x1n=cos(n/M)，其中M为正整数；(b) x2n=(-1)n。1.X1n图2.X2n图 n=linspace(-10,0.01,10); stem(-1).n,fill,-.);8.求x1n的自相关序列 n=(-10:10); %指定n的范围t=cos(n*pi); % x1n序列a,b=xcorr(t,n) %求得x1n自相关赋值给a，相关运算后得n赋给bstem(b,a); %以a为纵坐标，b为横坐标画图xlabel(Lag index); ylabel(Amplitude);a = 1.0000 -2.0000 3.0000

5、-4.0000 5.0000 -6.0000 7.0000 -8.0000 9.0000 -10.0000 11.0000 -12.0000 13.0000 -14.0000 15.0000 -16.0000 17.0000 -18.0000 19.0000 -20.0000 21.0000 -20.0000 19.0000 -18.0000 17.0000 -16.0000 15.0000 -14.0000 13.0000 -12.0000 11.0000 -10.0000 9.0000 -8.0000 7.0000 -6.0000 5.0000 -4.0000 3.0000 -2.0000

6、 1.0000b = -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 209.求x2n的自相关序列9.利用Matlab函数rand产生一个均匀分布的随机信号，并加到序列x1n和x2n上，画出受到干扰的序列y1n=x1n+ w1n和y2n=x2n+ w2n，其中w1n和w2n为随机信号；（1.）序列y1n=x1n+ w1n n=(-8:8); %指定n的范围a = rand(1,17 ） %产生随机的序列

7、t=cos(n*pi);y=(a+t) %将两序列相加stem(n,y,filled);hold on; %保留y的图像一面被后面的图像覆盖b,c=xcorr(y,n) %求自相关stem(c,b);xlabel(Lag index); ylabel(Amplitude);产生随机数a = 0.9157 0.7922 0.9595 0.6557 0.0357 0.8491 0.9340 0.6787 0.7577 0.7431 0.3922 0.6555 0.1712 0.7060 0.0318 0.2769 0.0462y =y1n=x1n+ w1n 1.9157 -0.2078 1.959

8、5 -0.3443 1.0357 -0.1509 1.9340 -0.3213 1.7577 -0.2569 1.3922 -0.3445 1.1712 -0.2940 1.0318 -0.7231 1.0462求自相关b = 2.0042 -1.6026 4.1769 -2.5546 5.6591 -2.7413 8.3359 -4.0543 11.5915 -4.9365 14.6138 -5.5930 15.6233 -6.2037 18.2083 -7.3129 21.9631 -7.3129 18.2083 -6.2037 15.6233 -5.5930 14.6138 -4.936

9、5 11.5915 -4.0543 8.3359 -2.7413 5.6591 -2.5546 4.1769 -1.6026 2.0042c = -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16（2.）序列y2n=x2n+ w2n产生随机数a = 0.6797 0.6551 0.1626 0.1190 0.4984 0.9597 0.3404 0.5853 0.2238 0.7513 0.2551 0.5060 0.6991 0.8909 0.9593

10、0.5472 0.1386y =x2n+ w2n 1.6797 -0.3449 1.1626 -0.8810 1.4984 -0.0403 1.3404 -0.4147 1.2238 -0.2487 1.2551 -0.4940 1.6991 -0.1091 1.9593 -0.4528 1.1386求自相关b = 1.9126 -1.1533 4.7710 -2.3886 7.2744 -3.9931 8.8302 -4.2434 10.7936 -5.1184 12.1991 -5.6320 14.9092 -7.7746 17.2574 -8.3803 20.9015 -8.3803 17.2574 -7.7746 14.9092 -5.6320 12.1991 -5.1184 10.7936 -4.2434 8.8302 -3.9931 7.2744 -2.3886 4.7710 -1.1533 1.9126c = -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16