2012-10-20 16:37:01 +00:00
|
|
|
program genmet
|
|
|
|
|
|
2013-01-22 21:04:47 +00:00
|
|
|
! Generate metric table for M-FSK modulation.
|
2012-10-20 16:37:01 +00:00
|
|
|
|
|
|
|
|
character*12 arg
|
|
|
|
|
real*4 r(0:255)
|
|
|
|
|
integer hist(2,-128:128)
|
|
|
|
|
data hist/514*0/,idum/-1/
|
|
|
|
|
|
|
|
|
|
lim(x)=min(127,max(-128,nint(scale*x)))
|
|
|
|
|
|
|
|
|
|
nargs=iargc()
|
|
|
|
|
if(nargs.ne.5) then
|
|
|
|
|
print*,'Usage: genmet ncoh nadd m0 snr iters'
|
|
|
|
|
go to 999
|
|
|
|
|
endif
|
|
|
|
|
call getarg(1,arg)
|
|
|
|
|
read(arg,*) ncoh
|
|
|
|
|
call getarg(2,arg)
|
|
|
|
|
read(arg,*) nadd
|
|
|
|
|
call getarg(3,arg)
|
|
|
|
|
read(arg,*) m0
|
|
|
|
|
call getarg(4,arg)
|
|
|
|
|
read(arg,*) snr
|
|
|
|
|
call getarg(5,arg)
|
|
|
|
|
read(arg,*) iters
|
|
|
|
|
|
|
|
|
|
ntones=2**m0
|
|
|
|
|
xm0=m0
|
|
|
|
|
scale=5.0
|
|
|
|
|
fac=sqrt(1.0/nadd)
|
|
|
|
|
s=sqrt(10.0**(0.1*snr))
|
|
|
|
|
hist=0
|
|
|
|
|
nerr=0
|
|
|
|
|
|
|
|
|
|
do iter=1,iters
|
|
|
|
|
do i=0,ntones-1
|
|
|
|
|
r(i)=0.
|
|
|
|
|
do n=1,nadd
|
|
|
|
|
x1=0.707*gran()
|
|
|
|
|
y1=0.707*gran()
|
|
|
|
|
if(i.eq.0) x1=x1+s
|
|
|
|
|
if(ncoh.eq.0) r(i)=r(i) + x1*x1 + y1*y1
|
|
|
|
|
if(ncoh.ne.0) r(i)=r(i) + x1
|
|
|
|
|
enddo
|
|
|
|
|
r(i)=fac*r(i)
|
|
|
|
|
enddo
|
|
|
|
|
do m=0,m0-1
|
|
|
|
|
n=2**m
|
|
|
|
|
r1=0.
|
|
|
|
|
r2=0.
|
|
|
|
|
do i=0,ntones-1
|
|
|
|
|
if(iand(i,n).ne.0) r1=max(r1,r(i))
|
|
|
|
|
if(iand(i,n).eq.0) r2=max(r2,r(i))
|
|
|
|
|
enddo
|
|
|
|
|
don=r2-r1
|
|
|
|
|
doff=r1-r2
|
|
|
|
|
if(don.lt.0.0) nerr=nerr+1
|
|
|
|
|
j1=lim(doff)
|
|
|
|
|
hist(1,j1)=hist(1,j1)+1
|
|
|
|
|
j2=lim(don)
|
|
|
|
|
hist(2,j2)=hist(2,j2)+1
|
|
|
|
|
enddo
|
|
|
|
|
enddo
|
|
|
|
|
|
|
|
|
|
do i=-128,127
|
|
|
|
|
write(13,1010) i/scale,hist(1,i)/(xm0*iters),hist(2,i)/(xm0*iters)
|
|
|
|
|
1010 format(f8.3,2f12.9)
|
|
|
|
|
enddo
|
|
|
|
|
|
|
|
|
|
ber=nerr/(xm0*iters)
|
|
|
|
|
write(*,1020) nadd,m0,snr,ber
|
|
|
|
|
1020 format('nadd:',i3,' m0:',i2,' snr: 'f5.1,' BER:',f8.3)
|
|
|
|
|
|
|
|
|
|
xln2=log(2.0)
|
|
|
|
|
do i=-128,127
|
|
|
|
|
p1=hist(2,i)/(xm0*iters)
|
|
|
|
|
p0=hist(1,i)/(xm0*iters)
|
|
|
|
|
if(p0+p1.eq.0.0 .and. i.lt.0) p0=1.e-6
|
|
|
|
|
if(p0+p1.eq.0.0 .and. i.gt.0) p1=1.e-6
|
|
|
|
|
xlhd0=log(max(0.001,2.0*p0/(p0+p1)))/xln2
|
|
|
|
|
xlhd1=log(max(0.001,2.0*p1/(p0+p1)))/xln2
|
|
|
|
|
write(14,1012) i/scale,xlhd0,xlhd1,p0/(p0+p1),p1/(p0+p1)
|
|
|
|
|
1012 format(f7.1,2f8.3,2f9.6)
|
|
|
|
|
enddo
|
|
|
|
|
|
|
|
|
|
999 end program genmet
|
|
|
|
|
|
