qpsk.rar_QPSK awgn误码率_QPSK信号误码率

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%qpsk ebn0indB=0:1:14; % Eb/N0 for i=1:length(ebn0indB); %ebn0=3; % Eb/N0 sr=256000.0; % Symbol rate ml=2; % ml:Number of modulation levels (BPSK:ml=1, QPSK:ml=2, 16QAM:ml=4,64QAM=16) br=sr .* ml; % Bit rate nd = 128; % Number of symbols that simulates in each loop IPOINT=8; A = [1 1/exp(1) 1/exp(2)]; N = 64; GI = 16; Mt = 1; Mr = 1; sig2 = 1e-3; N=64; %************************* Filter initialization *************************** irfn=21; % Number of 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 %******************** START CALCULATION ************************************* nloop=10; % Number of simulation loops noe = 0; % Number of error data nod = 0; % Number of transmitted data for iii=1:nloop %*************************** Data generation ******************************** data1=rand(1,nd*ml)>0.5; %*************************** QPSK Modulation ******************************** [ich,qch]=qpskmod(data1,1,nd,ml); [ich1,qch1]= compoversamp(ich,qch,length(ich),IPOINT); [ich2,qch2]= compconv(ich1,qch1,xh); %**************************** Attenuation Calculation *********************** spow=sum(ich2.*ich2+qch2.*qch2)/nd; attn=0.5*spow*sr/br*10.^(-ebn0indB(i)/10); attn=sqrt(attn); % sqrt: built in function %********************* Add White Gaussian Noise (AWGN) ********************** [ich3,qch3]= comb(ich2,qch2,attn);% add white gaussian noise [ich4,qch4]= compconv(ich3,qch3,xh2); syncpoint=irfn*IPOINT+1; ich5=ich4(syncpoint:IPOINT:length(ich4)); qch5=qch4(syncpoint:IPOINT:length(qch4)); %**************************** QPSK Demodulation ***************************** [demodata]=qpskdemod(ich1,qch1,1,nd,ml); %************************** Bit Error Rate (BER) **************************** noe2=sum(abs(data1-demodata)); nod2=length(data1); noe=noe+noe2; nod=nod+nod2; end % for iii=1:nloop %********************** Output result *************************** ber = noe/nod; s1(i)=ebn0indB(i); s2(i)=ber; %s3(i)=noe %s4(i)=nod semilogy(s1,s2,'r');axis([0, 14 ,0.1, 1]); end