mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-25 05:38:46 -05:00
d44e580148
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7734 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
198 lines
5.1 KiB
Fortran
198 lines
5.1 KiB
Fortran
program msk144sd
|
|
!
|
|
! A simple decoder for slow msk144.
|
|
! Can be used as a (slow) brute-force multi-decoder by looping
|
|
! over a set of carrier frequencies.
|
|
!
|
|
use options
|
|
use timer_module, only: timer
|
|
use timer_impl, only: init_timer
|
|
use readwav
|
|
|
|
parameter (NRECENT=10)
|
|
parameter (NSPM=864)
|
|
parameter (NPATTERNS=4)
|
|
|
|
character ch
|
|
character*80 line
|
|
character*500 infile
|
|
character*12 mycall,hiscall
|
|
character*6 mygrid
|
|
character(len=500) optarg
|
|
character*22 msgreceived
|
|
character*12 recent_calls(NRECENT)
|
|
|
|
complex cdat(30*375)
|
|
complex c(NSPM)
|
|
complex ct(NSPM)
|
|
|
|
real softbits(144)
|
|
real xmc(NPATTERNS)
|
|
|
|
logical :: display_help=.false.
|
|
|
|
type(wav_header) :: wav
|
|
|
|
integer iavmask(8)
|
|
integer iavpatterns(8,NPATTERNS)
|
|
integer npkloc(10)
|
|
|
|
integer*2 id2(30*12000)
|
|
integer*2 ichunk(7*1024)
|
|
|
|
data iavpatterns/ &
|
|
1,1,1,1,0,0,0,0, &
|
|
0,1,1,1,1,0,0,0, &
|
|
0,0,1,1,1,1,0,0, &
|
|
1,1,1,1,1,1,0,0/
|
|
data xmc/2.0,4.5,2.5,3.0/
|
|
|
|
type (option) :: long_options(2) = [ &
|
|
option ('frequency',.true.,'f','rxfreq',''), &
|
|
option ('help',.false.,'h','Display this help message','') &
|
|
]
|
|
t0=0.0
|
|
ntol=100
|
|
nrxfreq=1500
|
|
|
|
do
|
|
call getopt('f:h',long_options,ch,optarg,narglen,nstat,noffset,nremain,.true.)
|
|
if( nstat .ne. 0 ) then
|
|
exit
|
|
end if
|
|
select case (ch)
|
|
case ('f')
|
|
read (optarg(:narglen), *) nrxfreq
|
|
case ('h')
|
|
display_help = .true.
|
|
end select
|
|
end do
|
|
|
|
if(display_help .or. nstat.lt.0 .or. nremain.lt.1) then
|
|
print *, ''
|
|
print *, 'Usage: msk144sd [OPTIONS] file1 [file2 ...]'
|
|
print *, ''
|
|
print *, ' decode pre-recorded .WAV file(s)'
|
|
print *, ''
|
|
print *, 'OPTIONS:'
|
|
do i = 1, size (long_options)
|
|
call long_options(i) % print (6)
|
|
end do
|
|
go to 999
|
|
endif
|
|
|
|
call init_timer ('timer.out')
|
|
call timer('msk144 ',0)
|
|
ndecoded=0
|
|
do ifile=noffset+1,noffset+nremain
|
|
call get_command_argument(ifile,optarg,narglen)
|
|
infile=optarg(:narglen)
|
|
call timer('read ',0)
|
|
call wav%read (infile)
|
|
i1=index(infile,'.wav')
|
|
if( i1 .eq. 0 ) i1=index(infile,'.WAV')
|
|
read(infile(i1-6:i1-1),*,err=998) nutc
|
|
inquire(FILE=infile,SIZE=isize)
|
|
npts=min((isize-216)/2,360000)
|
|
read(unit=wav%lun) id2(1:npts)
|
|
close(unit=wav%lun)
|
|
call timer('read ',1)
|
|
|
|
! do if=1,89 ! brute force multi-decoder
|
|
fo=nrxfreq
|
|
! fo=(if-1)*25.0+300.0
|
|
call msksddc(id2,npts,fo,cdat)
|
|
np=npts/32
|
|
ntol=200 ! actual ntol is ntol/32=6.25 Hz. Detection window is 12.5 Hz wide
|
|
fc=1500.0
|
|
call msk144spd(cdat,np,ntol,ndecodesuccess,msgreceived,fc,fest,tdec,navg,ct, &
|
|
softbits,recent_calls,nrecent)
|
|
nsnr=0 ! need an snr estimate
|
|
if( ndecodesuccess .eq. 1 ) then
|
|
fest=fo+fest-fc ! fudging because spd thinks input signal is at 1500 Hz
|
|
goto 900
|
|
endif
|
|
! If short ping decoder doesn't find a decode
|
|
npat=NPATTERNS
|
|
do iavg=1,npat
|
|
iavmask=iavpatterns(1:8,iavg)
|
|
navg=sum(iavmask)
|
|
deltaf=4.0/real(navg) ! search increment for frequency sync
|
|
npeaks=4
|
|
ntol=200
|
|
fc=1500.0
|
|
call msk144sync(cdat(1:6*NSPM),6,ntol,deltaf,iavmask,npeaks,fc, &
|
|
fest,npkloc,nsyncsuccess,xmax,c)
|
|
if( nsyncsuccess .eq. 0 ) cycle
|
|
|
|
do ipk=1,npeaks
|
|
do is=1,3
|
|
ic0=npkloc(ipk)
|
|
if(is.eq.2) ic0=max(1,ic0-1)
|
|
if(is.eq.3) ic0=min(NSPM,ic0+1)
|
|
ct=cshift(c,ic0-1)
|
|
call msk144decodeframe(ct,softbits,msgreceived,ndecodesuccess, &
|
|
recent_calls,nrecent)
|
|
if(ndecodesuccess .gt. 0) then
|
|
tdec=tsec+xmc(iavg)*tframe
|
|
fest=fo+(fest-fc)/32.0
|
|
goto 900
|
|
endif
|
|
enddo !Slicer dither
|
|
enddo !Peak loop
|
|
enddo
|
|
|
|
! enddo
|
|
900 continue
|
|
if( ndecodesuccess .gt. 0 ) then
|
|
write(*,1020) nutc,nsnr,tdec,nint(fest),' % ',msgreceived,navg
|
|
1020 format(i6.6,i4,f5.1,i5,a3,a22,i4)
|
|
endif
|
|
enddo
|
|
|
|
call timer('msk144 ',1)
|
|
call timer('msk144 ',101)
|
|
go to 999
|
|
|
|
998 print*,'Cannot read from file:'
|
|
print*,infile
|
|
|
|
999 continue
|
|
end program msk144sd
|
|
|
|
subroutine msksddc(id2,npts,fc,cdat)
|
|
|
|
! The msk144 detector/demodulator/decoder will decode signals
|
|
! with carrier frequency, fc, in the range fN/4 +/- 0.03333*fN.
|
|
!
|
|
! For slow MSK144 with nslow=32:
|
|
! fs=12000/32=375 Hz, fN=187.5 Hz
|
|
!
|
|
! This routine accepts input samples with fs=12000 Hz. It
|
|
! downconverts and decimates by 32 to center a signal with input carrier
|
|
! frequency fc at new carrier frequency 1500/32=46.875 Hz.
|
|
! The analytic signal is returned.
|
|
|
|
parameter (NFFT1=30*12000,NFFT2=30*375)
|
|
integer*2 id2(npts)
|
|
complex cx(0:NFFT1)
|
|
complex cdat(30*375)
|
|
|
|
dt=1.0/12000.0
|
|
df=1.0/(NFFT1*dt)
|
|
icenter=int(fc/df+0.5)
|
|
i46p875=int(46.875/df+0.5)
|
|
ishift=icenter-i46p875
|
|
cx=cmplx(0.0,0.0)
|
|
cx(1:npts)=id2
|
|
call four2a(cx,NFFT1,1,-1,1)
|
|
cx=cshift(cx,ishift)
|
|
cx(1)=0.5*cx(1)
|
|
cx(2*i46p875+1:)=cmplx(0.0,0.0)
|
|
call four2a(cx,NFFT2,1,1,1)
|
|
cdat(1:npts/32)=cx(0:npts/32-1)/NFFT1
|
|
return
|
|
|
|
end subroutine msksddc
|
|
|