WSJT-X/lib/fst240/fst240sim.f90
2020-06-27 14:11:37 -05:00

144 lines
4.5 KiB
Fortran

program fst240sim
! Generate simulated signals for experimental slow FT4 mode
use wavhdr
use packjt77
include 'fst240_params.f90' !Set various constants
type(hdr) h !Header for .wav file
character arg*12,fname*17
character msg37*37,msgsent37*37,c77*77
complex, allocatable :: c0(:)
complex, allocatable :: c(:)
real, allocatable :: wave(:)
integer hmod
integer itone(NN)
integer*1 msgbits(101)
integer*2, allocatable :: iwave(:) !Generated full-length waveform
! Get command-line argument(s)
nargs=iargc()
if(nargs.ne.9) then
print*,'Need 9 arguments, got ',nargs
print*,'Usage: fst240sim "message" TRsec f0 DT h fdop del nfiles snr'
print*,'Examples: fst240sim "K1JT K9AN EN50" 60 1500 0.0 1 0.1 1.0 10 -15'
go to 999
endif
call getarg(1,msg37) !Message to be transmitted
call getarg(2,arg)
read(arg,*) nsec !TR sequence length, seconds
call getarg(3,arg)
read(arg,*) f00 !Frequency (only used for single-signal)
call getarg(4,arg)
read(arg,*) xdt !Time offset from nominal (s)
call getarg(5,arg)
read(arg,*) hmod !Modulation index, h
call getarg(6,arg)
read(arg,*) fspread !Watterson frequency spread (Hz)
call getarg(7,arg)
read(arg,*) delay !Watterson delay (ms)
call getarg(8,arg)
read(arg,*) nfiles !Number of files
call getarg(9,arg)
read(arg,*) snrdb !SNR_2500
nfiles=abs(nfiles)
twopi=8.0*atan(1.0)
fs=12000.0 !Sample rate (Hz)
dt=1.0/fs !Sample interval (s)
nsps=0
if(nsec.eq.15) nsps=800
if(nsec.eq.30) nsps=1680
if(nsec.eq.60) nsps=3888
if(nsec.eq.120) nsps=8200
if(nsec.eq.300) nsps=21504
if(nsps.eq.0) then
print*,'Invalid TR sequence length.'
go to 999
endif
baud=12000.0/nsps !Keying rate (baud)
nmax=nsec*12000
nz=nsps*NN
nz2=nsps*NN2
txt=nz2*dt !Transmission length (s)
tt=nsps*dt !Duration of symbols (s)
allocate( c0(0:nmax-1) )
allocate( c(0:nmax-1) )
allocate( wave(nmax) )
allocate( iwave(nmax) )
bandwidth_ratio=2500.0/(fs/2.0)
sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb)
if(snrdb.gt.90.0) sig=1.0
i3=-1
n3=-1
call pack77(msg37,i3,n3,c77)
call genfst240(msg37,0,msgsent37,msgbits,itone,iwspr)
write(*,*)
write(*,'(a9,a37)') 'Message: ',msgsent37
write(*,1000) f00,xdt,hmod,txt,snrdb
1000 format('f0:',f9.3,' DT:',f6.2,' hmod:',i6,' TxT:',f6.1,' SNR:',f6.1)
write(*,*)
if(i3.eq.1) then
write(*,*) ' mycall hiscall hisgrid'
write(*,'(28i1,1x,i1,1x,28i1,1x,i1,1x,i1,1x,15i1,1x,3i1)') msgbits(1:77)
else
write(*,'(a14)') 'Message bits: '
write(*,'(50i1,1x,24i1)') msgbits
endif
write(*,*)
write(*,'(a17)') 'Channel symbols: '
write(*,'(10i1)') itone
write(*,*)
! call sgran()
fsample=12000.0
icmplx=1
f0=f00+1.5*hmod*baud
call gen_fst240wave(itone,NN,nsps,nmax,fsample,hmod,f0,icmplx,c0,wave)
k=nint(xdt/dt)
c0=cshift(c0,-k)
if(k.gt.0) c0(0:k-1)=0.0
if(k.lt.0) c0(nmax+k:nmax-1)=0.0
do ifile=1,nfiles
c=c0
if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,nmax,NZ,fs,delay,fspread)
c=sig*c
wave=real(c)
if(snrdb.lt.90) then
do i=1,nmax !Add gaussian noise at specified SNR
xnoise=gran()
wave(i)=wave(i) + xnoise
enddo
endif
gain=100.0
if(snrdb.lt.90.0) then
wave=gain*wave
else
datpk=maxval(abs(wave))
fac=32766.9/datpk
wave=fac*wave
endif
if(any(abs(wave).gt.32767.0)) print*,"Warning - data will be clipped."
iwave=nint(wave)
h=default_header(12000,nmax)
if(nmax/12000.le.30) then
write(fname,1102) ifile
1102 format('000000_',i6.6,'.wav')
else
write(fname,1104) ifile
1104 format('000000_',i4.4,'.wav')
endif
open(10,file=trim(fname),status='unknown',access='stream')
write(10) h,iwave !Save to *.wav file
close(10)
write(*,1110) ifile,xdt,f00,snrdb,fname
1110 format(i4,f7.2,f8.2,f7.1,2x,a17)
enddo
999 end program fst240sim