Smldp510.m
上传用户:loeagle
上传日期:2013-03-02
资源大小:1236k
文件大小:2k
- function [p]=smldP510(snr_in_dB)
- % [p]=smldP510(snr_in_dB)
- % SMLDP510 simulates the probability of error for the given
- % snr_in_dB, signal-to-noise ratio in dB.
- M=4; % quaternary orthogonal signaling
- E=1;
- SNR=exp(snr_in_dB*log(10)/10); % signal-to-noise ratio per bit
- sgma=sqrt(E^2/(4*SNR)); % sigma, standard deviation of noise
- N=10000; % number of symbols being simulated
- % generation of the quaternary data source
- for i=1:N,
- temp=rand; % a uniform random variable over (0,1)
- if (temp<0.25),
- dsource1(i)=0;
- dsource2(i)=0;
- elseif (temp<0.5),
- dsource1(i)=0;
- dsource2(i)=1;
- elseif (temp<0.75),
- dsource1(i)=1;
- dsource2(i)=0;
- else
- dsource1(i)=1;
- dsource2(i)=1;
- end
- end;
- % detection, and probability of error calculation
- numoferr=0;
- for i=1:N,
- % matched filter outputs
- if ((dsource1(i)==0) & (dsource2(i)==0)),
- r0=sqrt(E)+gngauss(sgma);
- r1=gngauss(sgma);
- r2=gngauss(sgma);
- r3=gngauss(sgma);
- elseif ((dsource1(i)==0) & (dsource2(i)==1)),
- r0=gngauss(sgma);
- r1=sqrt(E)+gngauss(sgma);
- r2=gngauss(sgma);
- r3=gngauss(sgma);
- elseif ((dsource1(i)==1) & (dsource2(i)==0)),
- r0=gngauss(sgma);
- r1=gngauss(sgma);
- r2=sqrt(E)+gngauss(sgma);
- r3=gngauss(sgma);
- else
- r0=gngauss(sgma);
- r1=gngauss(sgma);
- r2=gngauss(sgma);
- r3=sqrt(E)+gngauss(sgma);
- end;
- % the detector
- max_r=max([r0 r1 r2 r3]);
- if (r0==max_r),
- decis1=0;
- decis2=0;
- elseif (r1==max_r),
- decis1=0;
- decis2=1;
- elseif (r2==max_r),
- decis1=1;
- decis2=0;
- else
- decis1=1;
- decis2=1;
- end;
- % Count the number of bit errors made in this decision.
- if (decis1~=dsource1(i)), % If it is an error, increase the error counter.
- numoferr=numoferr+1;
- end;
- if (decis2~=dsource2(i)), % If it is an error, increase the error counter.
- numoferr=numoferr+1;
- end;
- end;
- p=numoferr/(2*N); % bit error probability estimate