WSJT-X/lib/jt4sim.f90

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3.3 KiB
Fortran
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program jt4sim
! Generate simulated data for testing the JT4 decoder
use wavhdr
use packjt
use jt4
parameter (NMAX=60*12000)
type(hdr) h
integer*2 iwave(NMAX) !Generated waveform
real*4 dat(NMAX)
real*4 r(2)
real*8 f0,f,dt,twopi,phi,dphi0,dphi,baud,fspread,fsample,freq,sps
character message*22,msgsent*22,arg*8,fname*11,submode*1
integer*4 itone(206) !Channel symbols (values 0-8)
nargs=iargc()
if(nargs.ne.5) then
print*,'Usage: jt4sim "message" [A-G] fspread SNR nfiles'
print*,'Example: jt4sim "CQ K1ABC FN42" F 200 -17 1'
go to 999
endif
call getarg(1,message)
call fmtmsg(message,iz)
call getarg(2,arg)
read(arg,*) submode
mode4=ichar(submode) - ichar('A') + 1
call getarg(3,arg)
read(arg,*) fspread !Frequency spread (Hz)
call getarg(4,arg)
read(arg,*) snrdb !S/N in dB (2500 hz reference BW)
call getarg(5,arg)
read(arg,*) nfiles !Number of files
rmsdb=25.
rms=10.0**(0.05*rmsdb)
fsample=12000.d0 !Sample rate (Hz)
dt=1.d0/fsample !Sample interval (s)
twopi=8.d0*atan(1.d0)
npts=60*12000
sps=12000.d0/4.375d0 !2742.857...
f0=1000.d0 !Frequency of lowest tone (Hz)
freq=f0 !Silence compiler warning
dphi=0.0 !Silence compiler warning
call init_random_seed() ! seed Fortran RANDOM_NUMBER generator
call sgran() ! see C rand generator (used in gran)
h=default_header(12000,npts)
if(message(1:3).eq.'sin') read(message(4:),*) sinfreq
write(*,1000)
1000 format('File S/N Message'/ &
'--------------------------------')
call gen4(message,0,msgsent,itone,itype) !Encode message into tone #s
! write(*,1030) itone
!1030 format(/'Channel symbols'/(30i2))
do ifile=1,nfiles !Loop over all files
nmin=(ifile-1)*2
ihr=nmin/60
imin=mod(nmin,60)
write(fname,1002) ihr,imin !Create output filename
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
snrdbx=snrdb
sig=10.0**(0.05*snrdbx)
if(snrdb.gt.90.0) sig=1.0
write(*,1020) ifile,snrdbx,msgsent
1020 format(i3,f7.1,2x,a22)
phi=0.
baud=12000.d0/sps
isym0=0
k0=12000
do k=k0+1,npts
isym=1.d0 + (k-k0)/sps
if(isym.gt.206) exit
if(isym.ne.isym0) then
freq=f0 + itone(isym)*baud*nch(mode4)
if(message(1:3).eq.'sin') freq=sinfreq
dphi0=twopi*freq*dt
dphi=dphi0
isym0=isym
endif
if(fspread.gt.0.d0 .and. mod(k,120).eq.0) then
call random_number(r)
f=freq + 0.5*fspread*(r(1)+r(2)-1.0)
dphi=twopi*f*dt
endif
phi=phi + dphi
if(phi.gt.twopi) phi=phi-twopi
xphi=phi
dat(k)=dat(k) + sig*sin(xphi)
enddo
fac=32767.0
if(snrdb.ge.90.0) iwave(1:npts)=nint(fac*dat(1:npts))
if(snrdb.lt.90.0) iwave(1:npts)=nint(rms*dat(1:npts))
write(10) h,iwave(1:npts)
close(10)
enddo
999 end program jt4sim