WSJT-X/libm65/jt9sim.f90
Joe Taylor 94411a9061 Program jt9sim cleaned up in various ways. Final Fano decoding of
soft symbols moved to subroutine decode9.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2629 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2012-10-03 00:37:40 +00:00

159 lines
4.8 KiB
Fortran

program jt9sim
! Generate simulated data for testing of WSJT-X
parameter (NMAX=1800*12000)
integer ihdr(11)
integer*2 iwave !Generated waveform (no noise)
real*8 f0,f,dt,twopi,phi,dphi,baud,fspan
character msg*22,msg0*22,message*22,msgsent*22,arg*8,fname*11
integer*4 itone(85) !Channel symbols (values 0-8)
integer*4 i4DataSymNoGray(69) !Data Symbols, values 0-7
integer*1 i1ScrambledBits(207) !Hard-decision demodulated bits, interleaved
integer*1 i1Bits(207) !Encoded information-carrying bits
integer*1 i1SoftSymbols(207)
integer*1 i1
equivalence (i1,i4)
integer isync(85) !Sync vector
data isync/ &
1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0, &
1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0, &
0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0, &
0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0, &
1,0,0,0,1/
common/acom/dat(NMAX),iwave(NMAX)
nargs=iargc()
if(nargs.ne.6) then
print*,'Usage: jt9sim "message" fspan nsigs minutes SNR nfiles'
print*,'Example: "CQ K1ABC FN42" 200 20 2 -28 1'
print*,' '
print*,'Enter message = "" to use entries in msgs.txt.'
print*,'Enter SNR = 0 to generate a range of SNRs.'
go to 999
endif
call getarg(1,msg0)
message=msg0 !Transmitted message
call getarg(2,arg)
read(arg,*) fspan !Total freq range (Hz)
call getarg(3,arg)
read(arg,*) nsigs !Number of signals in each file
call getarg(4,arg)
read(arg,*) minutes !Length of file (1 2 5 10 30 minutes)
call getarg(5,arg)
read(arg,*) snrdb !S/N in dB (2500 hz reference BW)
call getarg(6,arg)
read(arg,*) nfiles !Number of files
rmsdb=25.
rms=10.0**(0.05*rmsdb)
f0=1500.d0 !Center frequency (MHz)
fsample=12000.d0 !Sample rate (Hz)
dt=1.d0/fsample !Sample interval (s)
twopi=8.d0*atan(1.d0)
npts=12000*(60*minutes-6)
nsps=0
if(minutes.eq.1) nsps=6912
if(minutes.eq.2) nsps=15360
if(minutes.eq.5) nsps=40960
if(minutes.eq.10) nsps=82944
if(minutes.eq.30) nsps=252000
if(nsps.eq.0) stop 'Bad value for minutes.'
ihdr=0 !Temporary ###
open(12,file='msgs.txt',status='old')
write(*,1000)
1000 format('File N freq S/N Message'/ &
'---------------------------------------------------')
do ifile=1,nfiles
nmin=(ifile-1)*2*minutes
ihr=nmin/60
imin=mod(nmin,60)
write(fname,1002) ihr,imin !Create the output filenames
1002 format('000000_',2i2.2)
open(10,file=fname//'.wav',access='stream',status='unknown')
if(snrdb.lt.90) then
do i=1,npts
dat(i)=gran()
enddo
else
dat(1:npts)=0.
endif
if(msg0.ne.' ') then
call genjt9(message,minutes,msgsent,itone)
endif
rewind 12
do isig=1,nsigs
if(msg0.eq.' ') then
read(12,1004) message
1004 format(a22)
call genjt9(message,minutes,msgsent,itone)
endif
f=f0
if(nsigs.gt.1) f=f0 - 0.5d0*fspan + fspan*(isig-1.d0)/(nsigs-1.d0)
snrdbx=snrdb
! if(snrdb.ge.-1.0) snrdbx=-15.0 - 15.0*(isig-1.0)/nsigs
sig=sqrt(2500.0/6000.0) * 10.0**(0.05*snrdbx)
write(*,1020) ifile,isig,f,snrdbx,msgsent
1020 format(i3,i4,f10.3,f7.1,2x,a22)
phi=0.
baud=12000.0/nsps
k=12000 !Start at t = 1 s
do isym=1,85
freq=f + itone(isym)*baud
dphi=twopi*freq*dt
do i=1,nsps
phi=phi + dphi
if(phi.lt.-twopi) phi=phi+twopi
if(phi.gt.twopi) phi=phi-twopi
xphi=phi
k=k+1
dat(k)=dat(k) + sig*sin(xphi) !Use lookup table for i*2 sin(x) ?
enddo
enddo
enddo
do i=1,npts
iwave(i)=nint(rms*dat(i))
enddo
write(10) ihdr,iwave(1:npts)
close(10)
! We're done! Now decode the data symbols from itone, as a test.
j=0
do i=1,85
if(isync(i).eq.1) cycle
j=j+1
i4DataSymNoGray(j)=igray(itone(i)-1,-1)
enddo
call unpackbits(i4DataSymNoGray,69,3,i1ScrambledBits)
call interleave9(i1ScrambledBits,-1,i1Bits)
do i=1,206
i4=-10
if(i1Bits(i).eq.1) i4=10
i4=i4+128
i1SoftSymbols(i)=i1
enddo
call decode9(i1SoftSymbols,msg)
if(msg.ne.msg0) print*,'Decode error: ',msg0,' ',msg
enddo
999 end program jt9sim