WSJT-X/lib/ft8/ft8sim.f90

139 lines
4.6 KiB
Fortran
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program ft8sim
! Generate simulated data for a 15-second HF/6m mode using 8-FSK.
! Output is saved to a *.wav file.
use wavhdr
include 'ft8_params.f90' !Set various constants
type(hdr) h !Header for .wav file
character arg*12,fname*17,sorm*1
character msg*22,msgsent*22
character*6 mygrid6
logical bcontest
complex c0(0:NMAX-1)
complex c(0:NMAX-1)
integer itone(NN)
integer*1 msgbits(KK)
integer*2 iwave(NMAX) !Generated full-length waveform
data mygrid6/'EM48 '/
! Get command-line argument(s)
nargs=iargc()
if(nargs.ne.8) then
print*,'Usage: ft8sim "message" s|m|d f0 DT fdop del nfiles snr'
print*,'Example: ft8sim "K1ABC W9XYZ EN37" m 1500.0 0.0 0.1 1.0 10 -18'
print*,'s|m|d: s for single signal, m for 25 signals, d for 5.'
print*,'f0 is ignored when sorm = m'
print*,'Make nfiles negative to invoke 72-bit contest mode.'
go to 999
endif
call getarg(1,msg) !Message to be transmitted
call getarg(2,sorm) !s for single signal, m for multiple sigs
if(sorm.eq."s") then
print*,"Generating single signal at 1500 Hz."
nsig=1
elseif( sorm.eq."m") then
print*,"Generating 25 signals per file."
nsig=25
elseif( sorm.eq."d") then
print*,"Generating 5 signals per file."
nsig=5
else
print*,"sorm parameter must be s, m, or d."
goto 999
endif
call getarg(3,arg)
read(arg,*) f0 !Frequency (only used for single-signal)
call getarg(4,arg)
read(arg,*) xdt !Time offset from nominal (s)
call getarg(5,arg)
read(arg,*) fspread !Watterson frequency spread (Hz)
call getarg(6,arg)
read(arg,*) delay !Watterson delay (ms)
call getarg(7,arg)
read(arg,*) nfiles !Number of files
call getarg(8,arg)
read(arg,*) snrdb !SNR_2500
bcontest=nfiles.lt.0
nfiles=abs(nfiles)
twopi=8.0*atan(1.0)
fs=12000.0 !Sample rate (Hz)
dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of symbols (s)
baud=1.0/tt !Keying rate (baud)
bw=8*baud !Occupied bandwidth (Hz)
txt=NZ*dt !Transmission length (s)
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
txt=NN*NSPS/12000.0
i3bit=0 ! ### TEMPORARY ??? ###
! Source-encode, then get itone()
call genft8(msg,mygrid6,bcontest,i3bit,msgsent,msgbits,itone)
write(*,1000) f0,xdt,txt,snrdb,bw,msgsent
1000 format('f0:',f9.3,' DT:',f6.2,' TxT:',f6.1,' SNR:',f6.1, &
' BW:',f4.1,2x,a22)
write(*,'(28i1,1x,28i1)') msgbits(1:56)
write(*,'(16i1)') msgbits(57:72)
write(*,'(3i1)') msgbits(73:75)
write(*,'(12i1)') msgbits(76:87)
! call sgran()
do ifile=1,nfiles
c=0.
do isig=1,nsig
c0=0.
if(nsig.eq.25) then
f0=(isig+2)*100.0
else if(nsig.eq.5) then
f0=1500.0 + (isig-1)*60.0
msg(3:3)=char(ichar('A')+isig-1)
msg(4:4)=char(ichar('A')+isig-1)
msg(5:5)=char(ichar('A')+isig-1)
call genft8(msg,mygrid6,bcontest,i3bit,msgsent,msgbits,itone)
endif
k=-1 + nint((xdt+0.5+0.01*gran())/dt)
! k=-1 + nint((xdt+0.5)/dt)
phi=0.0
do j=1,NN !Generate complex waveform
dphi=twopi*(f0+itone(j)*baud)*dt
do i=1,NSPS
k=k+1
phi=mod(phi+dphi,twopi)
if(k.ge.0 .and. k.lt.NMAX) c0(k)=cmplx(cos(phi),sin(phi))
enddo
enddo
if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c0,NMAX,fs,delay,fspread)
c=c+sig*c0
enddo
if(nsig.eq.5) call compress(c)
if(snrdb.lt.90) then
do i=0,NMAX-1 !Add gaussian noise at specified SNR
xnoise=gran()
ynoise=gran()
c(i)=c(i) + cmplx(xnoise,ynoise)
enddo
endif
fac=32767.0
rms=100.0
if(snrdb.ge.90.0) iwave(1:NMAX)=nint(fac*real(c))
if(snrdb.lt.90.0) iwave(1:NMAX)=nint(rms*real(c))
h=default_header(12000,NMAX)
write(fname,1102) ifile
1102 format('000000_',i6.6,'.wav')
open(10,file=fname,status='unknown',access='stream')
write(10) h,iwave !Save to *.wav file
close(10)
write(*,1110) ifile,xdt,f0,snrdb,fname
1110 format(i4,f7.2,f8.2,f7.1,2x,a17)
enddo
999 end program ft8sim