psk.rar_2PSK解调_MATLAB psk误码率_matlab psk信号_psk信号解调_误码率2PSK

clear all; close all; clc; max=10; g=zeros(1,max); g=randint(1,max);%产生长度为max的随机二进制序列% cp=[];mod1=[]; f=2*pi; t=0:2*pi/99:2*pi; for n=1:length(g); if g(n)==0; A=zeros(1,100); else g(n)==1; A=ones(1,100); end cp=[cp,A];%产生原始信号% c=cos(f*t); mod1=[mod1,c];%将载波变成与原始信号等长的矩阵形式% end figure(1) plot(cp); grid on; axis([0 100*length(g) -2 2]); title('二进制信号序列') cm=[]; for n=1:length(g); if g(n)==0; B=-ones(1,100); else g(n)==1; B=ones(1,100); end cm=[cm,B];%产生双极性码% end Y=cm.*mod1;%调制% figure(2) subplot(2,1,1) plot(Y); grid on; axis([0 100*length(g) -2 2]); title('2PSK调制信号'); subplot(2,1,2) plot(abs(fft(Y))); axis([0 100*length(g) 0 200]); title('2PSK调制信号频谱'); Z=awgn(Y,10);%加入信噪比为10的高斯白噪声% figure(3) subplot(2,1,1) plot(Z); grid on; axis([0 100*length(g) -2 2]); title('通过高斯白噪声信道后的的2PSK信号'); subplot(2,1,2) plot(abs(fft(Z))); axis([0 100*length(g) 0 200]); title('通过高斯白噪声信道后的的2PSK信号频谱'); W=2*mod1.*Z;%解调% fp=500;fs=700;rp=3;rs=20;fn=11025; ws=fs/(fn/2);wp=fp/(fn/2); [n,wn]=buttord(wp,ws,rp,rs);%计算巴特沃斯滤波器的阶数和截止频率% [b,a]=butter(n,wn);%计算巴特沃斯数字滤波器系统函数分子和分母多项式的系数向量a和b% W1=filter(b,a,W); figure(4) subplot(2,1,1) plot(W1) grid on; axis([0 100*length(g) -2 2]); title('经低通滤波器后的波形'); subplot(2,1,2) plot(abs(fft(W1))); axis([0 100*length(g) 0 200]); title('经低通滤波器后的频谱波形'); for m=1:100*length(g); if W1(m)<0; W1(m)=1; else W1(m)>=0; W1(m)=0; end end figure(5) subplot(2,1,1) plot(W1); grid on; axis([0 100*length(g) -2 2]); title('抽样判决后信号波形'); subplot(2,1,2) plot(abs(fft(W1))); axis([0 100*length(g) 0 200]); title('抽样判决后信号频谱波形'); rights=0; wrongs=0; for m=1:100*length(g) if (cp(1,m)==W1(m)) rights=rights+1; else wrongs=wrongs+1; end end Pe=wrongs/(wrongs+rights);