dpsk.m

使用matlab编程

N=8;
M=10;
fbconnection=[1 1 0 1 1 0 0 1];
mseq=m_sequence(fbconnection);
Seq=[mseq,1];
Ts = 2.5e-11;                                % time window (period):ps
num = 2^M;                              % number of points
dt = Ts/num;                              % timestep (dt)
% t = ((1:nt)')*dt;  
% w = wspace(T,nt);                       % angular frequency vector
% vs = fftshift(w/(2*pi)); 
P0=1;

ntt=Ts/2;
m=1;
CC=0;
FWHM=0.5e-11;
T0=FWHM/2/sqrt(log(2));
Number=length(Seq)*num;
if Seq(1)==0
    E(1)=0;
else
    E(1)=pi;
end

for k=2:length(Seq)
    if Seq(k)==0
        E(k)=E(k-1);
    else
        E(k)=pi-E(k-1);
    end
end

t=zeros(1,Number);
Es=zeros(1,Number);
Ess=zeros(1,Number);
time=zeros(1,Number);
for k=1:1:Number
    t(k)=dt*(k-1);
    Es(k)=sqrt(P0)*Seq(fix(t(k)/Ts)+1)*exp(-(1+i*CC)/2*((t(k)-(fix(t(k)/Ts)*Ts)-ntt)/T0)^(2*m));
end
%    E=awgn(E,10,'measured');
for k=1:1:Number
    t(k)=dt*(k-1);
    Ess(k)=sqrt(P0)*exp(-(1+i*CC)/2*((t(k)-(fix(t(k)/Ts)*Ts)-ntt)/T0)^(2*m))*exp(i*E(fix(t(k)/Ts)+1));
end

Ess=awgn(Ess,10,'measured');
% Ess=Es;
figure
subplot(3,1,1)
% plot(Es)
plot(t(1:2^14),Es(1:2^14),'k')       % 产生的高斯信号
title('2^8个高斯信号');
subplot(3,1,2)
plot(E(1:16),'k')
subplot(3,1,3)
plot(t(1:2^14),abs(Ess(1:2^14)),'k')