mirror of https://github.com/saitohirga/WSJT-X.git
73 lines
2.4 KiB
Fortran
73 lines
2.4 KiB
Fortran
subroutine jtmsk(dat,npts,cfile6,tpk,mswidth,ndb,nrpt,Nfreeze, &
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ntol,MouseDF,pick,mycall)
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! Decode a JTMSK ping
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parameter (NZ=2*48000)
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real dat(npts) !Raw data
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complex cdat(NZ) !Analytic form of signal
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character*6 cfile6 !FileID
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logical pick
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character*12 mycall
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real s(NZ) !Power spectrum
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real s2(0:63,400)
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real r(60000)
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complex cw(168,0:63) !Complex waveforms for all codewords
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complex cwb(168) !Complex waveform for <space>
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logical first
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character msg*400,msg29*29
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data first/.true./
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save first,cw,cwb
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save cdat !Fix its address, for four2
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if(first) call setupmsk(cw,cwb) !Calculate waveforms for codewords
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first=.false.
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nsps=24 !Samples per symbol
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f0=1000.0 !Nominal frequency for bit=0
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n=log(float(npts))/log(2.0) + 1.0
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nfft1=2**n !FFT length
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call analytic(dat,npts,nfft1,s,cdat) !Convert to analytic signal
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call mskdf(cdat,npts,tpk,nfft1,f0,nfreeze,mousedf,ntol, &
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dfx,snrsq2) !Get DF
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sq2lim=7.0
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if(pick) sq2lim=5.0
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if(snrsq2.lt.sq2lim) go to 900 !Reject non-JTMS signals
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call tweak1(cdat,npts,-dfx,cdat) !Mix to standard frequency
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call syncmsk(cdat,npts,cwb,r,i1) !Get character sync
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call lenmsk(r,npts,msglen) !Find message length
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s2=0.
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nchar=(npts-168+1-i1)/168
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if(nchar.gt.400) nchar=400
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call decodemsk(cdat,npts,cw,i1,nchar,s2,msg) !Decode the message
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ia=1
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if(nchar.ge.40) ia=min(nchar/3,nchar-28)
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ib=min(ia+28,nchar) !Can better limits ia, ib be found?
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msg29=adjustl(msg(ia:ib))
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msg=adjustl(msg)
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ib=min(nchar,45)
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ndf=nint(dfx)
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nchk=max(20,nint(1.5*msglen))
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if(msglen.eq.0 .or. nchar.lt.nchk .or. pick) then
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write(*,1110) cfile6,tpk,mswidth,ndb,nrpt,ndf,msg(1:45)
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1110 format(a6,f5.1,i5,i3,1x,i2.2,i5,5x,a45)
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endif
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if(msglen.gt.0 .and. nchar.ge.nchk) then
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call foldmsk(s2,msglen,nchar,mycall,msg,msg29) !Decode folded message
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write(*,1120) cfile6,tpk,mswidth,ndb,nrpt,ndf,msg29
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1120 format(a6,f5.1,i5,i3,1x,i2.2,i5,5x,a29,11x,'*')
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endif
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900 continue
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return
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end subroutine jtmsk
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