1、通信系統建模與仿真實驗一、高斯白噪聲的matlab實現要求： 樣本點：100 1000 標準差：0.2 2 10 均值： 0 0.2白噪聲 如果噪聲的功率譜密度在所有的頻率上均為一常數，即式中：為常數，責成該噪聲為白噪聲，用表示。高斯白噪聲的matlab實現1樣本點為1000、均值為0、標準差為0.2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:1000; for i = 1:length(f) K = (0.2) * randn(1,1) - 0; P(i) = 10.(K - 3.95*(10-5)*f(i)

2、; A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)2樣本點為1000、均值為0、標準差為2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:1000; for i = 1:length(f) K = (2) * randn(1,1) - 0; P(i) = 10.

3、(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)3樣本點為1000、均值為0、標準差為10時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:1000; for i = 1:length(f) K = (10) * ran

4、dn(1,1) - 0; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)4樣本點為1000、均值為10、標準差為0.2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:1000; for i = 1

5、:length(f) K = (0.2) * randn(1,1) - 10; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)5樣本點為1000、均值為10、標準差為2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear al

6、l f = 1:1:1000; for i = 1:length(f) K = (2) * randn(1,1) - 10; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)6樣本點為1000、均值為10、標準差為10時，高斯白噪聲分布為下圖所示：程序如下所示：% White

7、background nois clear all f = 1:1:1000; for i = 1:length(f) K = (10) * randn(1,1) - 10; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)7樣本點為100、均值為0、標準差為0.2時，高斯白噪

8、聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (0.2) * randn(1,1) - 0; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)8樣本點

9、為100、均值為0、標準差為2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (2) * randn(1,1) - 0; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);

10、plot(ti,realx2)9.樣本點為100、均值為0、標準差為10時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (10) * randn(1,1) - 0; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) =

11、realx(2:length(xifft);plot(ti,realx2)10. 樣本點為100、均值為10、標準差為0.2時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (0.2) * randn(1,1) - 10; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;

12、realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)11. 樣本點為100、均值為10、標準差為10時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (2) * randn(1,1) - 10; P(i) = 10.(K - 3.95*(10-5)*f(i); A(i) = sqrt(2*P(i); endxifft = ifft(A);realx = real(xifft);ti = 1:length(xifft)-1/1000;realx2(1:length(xifft)-1) = realx(2:length(xifft);plot(ti,realx2)12.樣本點為100、均值為0、標準差為10時，高斯白噪聲分布為下圖所示：程序如下所示：% White background nois clear all f = 1:1:100; for i = 1:length(f) K = (10) * ra