bpsk.m

BPSK 调制在 AWGN 信道下的 性能仿真

clc;
framelength = 1000;
snr_db=-3:0.5:8; 
snr=10.^(snr_db/10);  
for i=1:length(snr)    
    errors = 0;
    sigma = sqrt(1/(2*snr(i)));
    num_frame = 0;
    while
   (errors<1000 && num_frame<=10000)
   num_frame=num_frame+1; 
   msg=randsrc(1,framelength,[0,1]); 
   x=pskmod(msg,2);   
   y=x+randn(1,length(x))*sigma; 
   c=pskdemod(y,2);   
   errors=errors+length(find(c(1:framelength)~=msg));  
    end
    ber(i) = errors/(num_frame*framelength);
end
edn0_db=-3:0.5:8;
a=10.^(edn0_db/10);
br=0.5*erfc(sqrt(a));
figure;semilogy(edn0_db,br,snr_db,ber,'o');
grid