3.用到的程序 ①M元正交调制解调 M=16; Fc=10; Fd=1; Fs=50;
x=randint(100,1,M);
y=domd(x,Fc,Fd,Fs,'qask',M); ynoisy=y+.01*randn(Fs/Fd*100,1); z=demod(ynoisy,Fc,Fd,Fs,'qask',M); s=symerr(x,z); t=0.1:0.1:10;
subplot(2,1,1);
plot(t,x');title('?D?o?') subplot(2,1,2);
plot(t,z');title('?μ÷???aμ÷oóμ?D?o?') figure;modmap('qask',M) ②基带调制解调 M=4; Fd=1; Fs=32; SURperBit=5;
adjSNR=SNRperBit-10*log10(Fs/Fd)+10*log10(log2( M)); x=randint(5000),1,M); tone=0.5;
randn('state'1945724);
w1=dmodce(x,Fd,Fs,'fsk'M,tone); y1=awgn(w1,adjSNR,'measured'[],'dB'); z1=ddemodce(y1,Fd,Fs'fsk'M,tone); ser1=symeer(x,z1); tone=0.25;
randn('state'1945726);
w2=dmodce(x,Fd,Fs,'fsk'M,tone); y2=awgn(w2,adjSNR,'measured'[],'dB');
z2=ddemodce(y2,Fd,Fs'fsk'M,tone); ser2=symeer(x,z2); ③模数转换 a=4; f0=0.02; L=50; n=1:(L-1);
x=a.*cos(2.*pi.*f0.*n); bit=5; range=2^5; plot(x);
interval=(a*2)/(range-1); partition = [-a:interval:a]; interval2 = (a*2)/(range) codebook=[-a:interval2:a];
[index quantized]= quantiz(x,partition,codebook); plot(n,x,'x',n,quantized,'.');
legend('Original signal','Quantized signal'); 四 结束语
在MATLAB的学习中不仅要在课堂上学认真学习，最重要的还是在课后的学习,在平时的学习当中要不断的探索不断的研究才能将所学知识掌握的更牢固。