mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-12-24 11:40:31 -05:00
3124648fbc
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7636 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
186 lines
5.2 KiB
Fortran
186 lines
5.2 KiB
Fortran
program fsk4sim
|
|
|
|
parameter (ND=60) !Data symbols: LDPC (120,60), r=1/2
|
|
parameter (NN=ND) !Total symbols (60)
|
|
parameter (NSPS=57600) !Samples per symbol at 12000 sps
|
|
parameter (NZ=NSPS*NN) !Samples in waveform (3456000)
|
|
|
|
character*8 arg
|
|
complex c(0:NZ-1) !Complex waveform
|
|
complex cr(0:NZ-1)
|
|
complex cs(NSPS,NN)
|
|
complex cps(0:3)
|
|
complex ct(0:2*NN-1)
|
|
complex z,w,zsum
|
|
real r(0:NZ-1)
|
|
real s(NSPS,NN)
|
|
real savg(NSPS)
|
|
real tmp(NN) !For generating random data
|
|
real xnoise(0:NZ-1) !Generated random noise
|
|
real ps(0:3)
|
|
integer id(NN) !Encoded 2-bit data (values 0-3)
|
|
integer id2(NN) !Recovered data
|
|
equivalence (r,cr)
|
|
|
|
nnn=0
|
|
nargs=iargc()
|
|
if(nargs.ne.6) then
|
|
print*,'Usage: fsk8sim f0 delay(ms) fspread(Hz) nts iters snr(dB)'
|
|
go to 999
|
|
endif
|
|
call getarg(1,arg)
|
|
read(arg,*) f0 !Low tone frequency
|
|
call getarg(2,arg)
|
|
read(arg,*) delay
|
|
call getarg(3,arg)
|
|
read(arg,*) fspread
|
|
call getarg(4,arg)
|
|
read(arg,*) nts
|
|
call getarg(5,arg)
|
|
read(arg,*) iters
|
|
call getarg(6,arg)
|
|
read(arg,*) snrdb
|
|
|
|
twopi=8.d0*atan(1.d0)
|
|
fs=12000.d0
|
|
dt=1.0/fs
|
|
ts=NSPS*dt
|
|
baud=1.d0/ts
|
|
txt=NZ*dt
|
|
bandwidth_ratio=2500.0/6000.0
|
|
write(*,1000) baud,5*baud,txt,delay,fspread,nts
|
|
1000 format('Baud:',f6.3,' BW:',f5.1,' TxT:',f5.1,' Delay:',f5.2, &
|
|
' fSpread:',f5.2,' nts:',i3/)
|
|
|
|
write(*,1004)
|
|
1004 format(' SNR Sym Bit SER BER Sym Bit SER BER'/59('-'))
|
|
|
|
isna=-25
|
|
isnb=-40
|
|
if(snrdb.ne.0.0) then
|
|
isna=nint(snrdb)
|
|
isnb=isna
|
|
endif
|
|
do isnr=isna,isnb,-1
|
|
snrdb=isnr
|
|
sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb)
|
|
if(snrdb.gt.90.0) sig=1.0
|
|
nhard1=0
|
|
nhard2=0
|
|
nbit1=0
|
|
nbit2=0
|
|
nh2=0
|
|
nb2=0
|
|
do iter=1,iters
|
|
nnn=nnn+1
|
|
id=0
|
|
call random_number(tmp)
|
|
where(tmp.ge.0.25 .and. tmp.lt.0.50) id=1
|
|
where(tmp.ge.0.50 .and. tmp.lt.0.75) id=2
|
|
where(tmp.ge.0.75) id=3
|
|
|
|
call genfsk4(id,f0,nts,c) !Generate the 4-FSK waveform
|
|
call watterson(c,delay,fspread)
|
|
if(sig.ne.1.0) c=sig*c !Scale to requested SNR
|
|
if(snrdb.lt.90) then
|
|
do i=0,NZ-1 !Generate gaussian noise
|
|
xnoise(i)=gran()
|
|
enddo
|
|
endif
|
|
r(0:NZ-1)=real(c(0:NZ-1)) + xnoise !Add noise to signal
|
|
|
|
call snr2_wsprlf(r,freq,snr2500,width,1)
|
|
write(*,3001) freq,snr2500,width
|
|
3001 format(40x,3f10.3)
|
|
|
|
df=12000.0/(2*NSPS)
|
|
! i0=nint(f0/df)
|
|
! i0=nint((1500.0+freq)/df)
|
|
i0=nint((f0+freq)/df)
|
|
call spec4(r,cs,s,savg)
|
|
|
|
do j=1,NN
|
|
nlo=0
|
|
nhi=0
|
|
ps=s(i0:i0+6*nts:2*nts,j)
|
|
cps=cs(i0:i0+6*nts:2*nts,j)
|
|
if(max(ps(1),ps(3)).ge.max(ps(0),ps(2))) nlo=1
|
|
if(max(ps(2),ps(3)).ge.max(ps(0),ps(1))) nhi=1
|
|
id2(j)=2*nhi+nlo
|
|
z=cps(id2(j))
|
|
ct(j-1)=z
|
|
enddo
|
|
nh1=count(id.ne.id2)
|
|
nb1=count(iand(id,1).ne.iand(id2,1)) + count(iand(id,2).ne.iand(id2,2))
|
|
|
|
ct(NN:)=0.
|
|
call four2a(ct,2*NN,1,-1,1)
|
|
df2=baud/(2*NN)
|
|
ct=cshift(ct,NN)
|
|
ppmax=0.
|
|
dfpk=0.
|
|
do i=0,2*NN-1
|
|
f=(i-NN)*df2
|
|
pp=real(ct(i))**2 + aimag(ct(i))**2
|
|
if(pp.gt.ppmax) then
|
|
ppmax=pp
|
|
dfpk=f
|
|
endif
|
|
enddo
|
|
|
|
zsum=0.
|
|
do j=1,NN
|
|
phi=(j-1)*twopi*dfpk*ts
|
|
w=cmplx(cos(phi),sin(phi))
|
|
cps=cs(i0:i0+6*nts:2*nts,j)*conjg(w)
|
|
z=cps(id2(j))
|
|
ct(j)=z
|
|
zsum=zsum+z
|
|
write(12,1042) j,id(j),id2(j),20*ps,atan2(aimag(z),real(z)), &
|
|
atan2(aimag(zsum),real(zsum)),zsum
|
|
1042 format(3i2,6f8.3,2f8.1)
|
|
enddo
|
|
|
|
phi0=atan2(aimag(zsum),real(zsum))
|
|
zsum=0.
|
|
do j=1,NN
|
|
phi=(j-1)*twopi*dfpk*ts + phi0
|
|
w=cmplx(cos(phi),sin(phi))
|
|
nlo=0
|
|
nhi=0
|
|
cps=cs(i0:i0+6*nts:2*nts,j)*conjg(w)
|
|
ps=real(cps)
|
|
if(max(ps(1),ps(3)).ge.max(ps(0),ps(2))) nlo=1
|
|
if(max(ps(2),ps(3)).ge.max(ps(0),ps(1))) nhi=1
|
|
id2(j)=2*nhi+nlo
|
|
z=cps(id2(j))
|
|
ct(j)=z
|
|
zsum=zsum+z
|
|
enddo
|
|
|
|
nh2=count(id.ne.id2)
|
|
nb2=count(iand(id,1).ne.iand(id2,1)) + count(iand(id,2).ne.iand(id2,2))
|
|
nhard1=nhard1+nh1
|
|
nhard2=nhard2+nh2
|
|
nbit1=nbit1+nb1
|
|
nbit2=nbit2+nb2
|
|
|
|
fdiff=1500.0+freq - f0
|
|
write(13,1040) snrdb,snr2500,f0,fdiff,width,nh1,nb1,nh2,nb2
|
|
1040 format(2f7.1,f9.2,f7.2,f6.1,2(i8,i6))
|
|
40 continue
|
|
enddo
|
|
|
|
ser1=float(nhard1)/(NN*iters)
|
|
ser2=float(nhard2)/(NN*iters)
|
|
ber1=float(nbit1)/(2*NN*iters)
|
|
ber2=float(nbit2)/(2*NN*iters)
|
|
write(*,1050) snrdb,nhard1,nbit1,ser1,ber1,nhard2,nbit2,ser2,ber2
|
|
write(14,1050) snrdb,nhard1,nbit1,ser1,ber1,nhard2,nbit2,ser2,ber2
|
|
1050 format(f6.1,2(2i5,2f8.4))
|
|
enddo
|
|
write(*,1060) NN*iters,2*NN*iters
|
|
1060 format(59('-')/'Max: ',2i5)
|
|
|
|
999 end program fsk4sim
|