mpsk.m

PSK调制程序

% 有过采样的mpsk.m
%
% Simulation program to realize BPSK transmission system
%
% Programmed by snowflier,
%

%******************** basic information of the signal **********************

sr=100.0; % Symbol rate
ml=2; % Number of modulation levels(bpsk)1->bpsk,2->4psk,3->8psk
M=2^ml
br=sr.*ml;   % Bit rate (=symbol rate in this case)
nd = 10;   % Number of symbols that simulates in each loop
%ebn0=3;      % Eb/N0
IPOINT=100;    % Number of oversamples
T=nd/sr;
fc=10/T;

%******************** Data generation ********************************  
for i=1:nd
    temp=rand;
    data(i)=1+floor(M*temp);
end
	
        [data1]=oversamp(data,nd,IPOINT);

%******************* Filter initialization ********************

irfn=21;     % Number of filter taps          
alfs=0.5;    % Rolloff factor
[xh] = hrollfcoef(irfn,IPOINT,sr,alfs,1);   %Transmitter filter coefficients  
%[xh2] = hrollfcoef(irfn,IPOINT,sr,alfs,0);  %Receiver filter coefficients

         %data=conv(data,xh);
%********************modulation********************************
 delta_T=T/length(data1);
 t=delta_T:delta_T:T;
 b=zeros(1,length(data1));
 bpsk=zeros(1,length(data1));
 for i=1:100:length(data1)
     %b=cos(2*pi*fc*t+pi*data1(i));
     theta(i)=((2*pi)*(data1(i)-1))/M;
     b=exp(j*(2*pi*fc*t+theta(i)));
     bpsk(i:i+99)=b(i:i+99);
 end
 f=-0.5/delta_T:1/(delta_T*(length(data1)-1)):0.5/delta_T;
 BPSK=abs(fft(bpsk));
 subplot(211);
 plot(real(bpsk));
 M=500;
 Rx=zeros(1,M+1);
 Sx=zeros(1,M+1);
 Rx=Rx_est(real(bpsk),M);
 Sx=fftshift(abs(fft(Rx)));
 subplot(212);
 plot(f,fftshift(BPSK));
 c=cwt(bpsk,1:40,'Haar');x=zeros(1,length(abs(c(2,:))));x=abs(c(2,:));figure,plot(x)
 figure,plot(Sx);