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https://github.com/saitohirga/WSJT-X.git
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470 lines
13 KiB
Fortran
470 lines
13 KiB
Fortran
module q65
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parameter (NSTEP=8) !Time bins per symbol, in s1() and s1a()
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parameter (PLOG_MIN=-240.0) !List decoding threshold
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integer nsave,nlist,LL0
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integer listutc(10)
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integer apsym0(58),aph10(10)
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integer apmask(13),apsymbols(13)
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integer,dimension(22) :: isync = (/1,9,12,13,15,22,23,26,27,33,35, &
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38,46,50,55,60,62,66,69,74,76,85/)
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integer codewords(63,206)
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integer navg,ibwa,ibwb,ncw,nsps,mode_q65,istep,nsmo,lag1,lag2
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integer i0,j0
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real,allocatable,save :: s1a(:,:) !Cumulative symbol spectra
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real sync(85) !sync vector
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real df,dtstep
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contains
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subroutine q65_dec0(nutc,iwave,ntrperiod,nfqso,ntol,ndepth,lclearave, &
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emedelay,xdt,f0,snr1,width,dat4,snr2,idec)
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! Top-level routine in q65 module
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! Input: iwave(0:nmax-1) Raw data
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! ntrperiod T/R sequence length (s)
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! nfqso Target frequency (Hz)
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! ntol Search range around nfqso (Hz)
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! ndepth Requested decoding depth
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! lclearave Flag to clear the accumulating array
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! emedelay Extra delay for EME signals
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! Output: xdt Time offset from nominal (s)
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! f0 Frequency of sync tone
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! snr1 Relative SNR of sync signal
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! width Estimated Doppler spread
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! dat4(13) Decoded message as 13 six-bit integers
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! snr2 Estimated SNR of decoded signal
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! idec Flag for decing results
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! -1 No decode
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! 0 No AP
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! 1 "CQ ? ?"
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! 2 "Mycall ? ?"
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! 3 "MyCall HisCall ?"
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use packjt77
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use timer_module, only: timer
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parameter (LN=2176*63) !LN=LL*NN; LL=64*(mode_q65+2), NN=63
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integer*2 iwave(0:12000*ntrperiod-1) !Raw data
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integer dat4(13)
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character*37 decoded
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logical first,lclearave
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real, allocatable :: s1(:,:) !Symbol spectra, 1/8-symbol steps
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real, allocatable :: s3(:,:) !Data-symbol energies s3(LL,63)
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real, allocatable :: ccf(:,:) !CCF(freq,lag)
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real, allocatable :: ccf1(:) !CCF(freq) at best lag
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real, allocatable :: ccf2(:) !CCF(freq) at any lag
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data first/.true./
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save first
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if(nutc+ndepth.eq.-999) stop !Silence compiler warnings
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! Set seom parameters and allocate storage for large arrays
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irc=-2
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idec=-1
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snr1=0.
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dat4=0
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LL=64*(2+mode_q65)
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nfft=nsps
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df=12000.0/nfft !Freq resolution = baud
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istep=nsps/NSTEP
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iz=5000.0/df !Uppermost frequency bin, at 5000 Hz
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txt=85.0*nsps/12000.0
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jz=(txt+1.0)*12000.0/istep !Number of symbol/NSTEP bins
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if(nsps.ge.6912) jz=(txt+2.0)*12000.0/istep !For TR 60 s and higher
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ia=ntol/df
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ia2=max(ia,10*mode_q65,nint(100.0/df))
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nsmo=int(0.7*mode_q65*mode_q65)
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if(nsmo.lt.1) nsmo=1
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if(first) then !Generate the sync vector
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sync=-22.0/63.0 !Sync tone OFF
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do k=1,22
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sync(isync(k))=1.0 !Sync tone ON
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enddo
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endif
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allocate(s1(iz,jz))
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allocate(s3(-64:LL-65,63))
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allocate(ccf(-ia2:ia2,-53:214))
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allocate(ccf1(-ia2:ia2))
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allocate(ccf2(-ia2:ia2))
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if(LL.ne.LL0 .or. lclearave) then
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if(allocated(s1a)) deallocate(s1a)
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allocate(s1a(iz,jz))
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s1a=0.
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navg=0
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LL0=LL
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endif
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dtstep=nsps/(NSTEP*12000.0) !Step size in seconds
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lag1=-1.0/dtstep
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lag2=1.0/dtstep + 0.9999
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if(nsps.ge.3600 .and. emedelay.gt.0) lag2=4.0/dtstep + 0.9999 !Include EME
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j0=0.5/dtstep
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if(nsps.ge.7200) j0=1.0/dtstep !Nominal start-signal index
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s3=0.
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call timer('s1 ',0)
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! Compute symbol spectra with NSTEP time bins per symbol
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call q65_symspec(iwave,ntrperiod*12000,iz,jz,s1)
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call timer('s1 ',1)
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i0=nint(nfqso/df) !Target QSO frequency
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if(i0-64.lt.1 .or. i0-65+LL.gt.iz) go to 900 !Frequency out of range
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call pctile(s1(i0-64:i0-65+LL,1:jz),LL*jz,40,base)
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s1=s1/base
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! Apply fast AGC to the symbol spectra
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s1max=20.0 !Empirical choice
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do j=1,jz !### Maybe wrong way? ###
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smax=maxval(s1(i0-64:i0-65+LL,j))
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if(smax.gt.s1max) s1(i0-64:i0-65+LL,j)=s1(i0-64:i0-65+LL,j)*s1max/smax
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enddo
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dat4=0
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if(ncw.gt.0) then
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! Try list decoding via "Deep Likelihood".
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call timer('ccf_85 ',0)
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! Try to synchronize using all 85 symbols
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call q65_ccf_85(s1,iz,jz,nfqso,ia,ia2,ipk,jpk,f0,xdt,imsg_best,ccf,ccf1)
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call timer('ccf_85 ',1)
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call timer('list_dec',0)
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call q65_dec_q3(s1,iz,jz,s3,LL,ipk,jpk,snr2,dat4,idec,decoded)
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call timer('list_dec',1)
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if(idec.ne.0) then
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ic=ia2/4;
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base=(sum(ccf1(-ia2:-ia2+ic)) + sum(ccf1(ia2-ic:ia2)))/(2.0+2.0*ic);
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ccf1=ccf1-base
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smax=maxval(ccf1)
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if(smax.gt.10.0) ccf1=10.0*ccf1/smax
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base=(sum(ccf2(-ia2:-ia2+ic)) + sum(ccf2(ia2-ic:ia2)))/(2.0+2.0*ic);
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ccf2=ccf2-base
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smax=maxval(ccf2)
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if(smax.gt.10.0) ccf2=10.0*ccf2/smax
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endif
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endif
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! Get 2d CCF and ccf2 using sync symbols only
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call q65_ccf_22(s1,iz,jz,nfqso,ia,ia2,ipk,jpk,f0,xdt,ccf,ccf2)
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! Estimate rms on ccf baseline
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sq=0.
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nsq=0
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jd=(lag2-lag1)/4
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do i=-ia2,ia2
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do j=lag1,lag2
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if(abs(j-jpk).gt.jd .and. abs(i-ipk).gt.ia/2) then
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sq=sq + ccf(i,j)**2
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nsq=nsq+1
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endif
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enddo
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enddo
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rms=sqrt(sq/nsq)
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smax=ccf(ipk,jpk)
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snr1=smax/rms
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ccf2=ccf2/rms
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if(snr1.gt.10.0) ccf2=(10.0/snr1)*ccf2
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if(idec.le.0) then
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! The q3 decode attempt failed. Copy synchronied symbol spectra from s1
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! into s3 and prepare to try a more general decode.
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ccf1=ccf(:,jpk)/rms
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if(snr1.gt.10.0) ccf1=(10.0/snr1)*ccf1
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call q65_s1_to_s3(s1,iz,jz,ipk,jpk,LL,mode_q65,sync,s3)
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endif
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smax=maxval(ccf1)
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i1=-9999
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i2=-9999
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do i=-ia,ia
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if(i1.eq.-9999 .and. ccf1(i).ge.0.5*smax) i1=i
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if(i2.eq.-9999 .and. ccf1(-i).ge.0.5*smax) i2=-i
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enddo
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width=df*(i2-i1)
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! Write data for the red and orange sync curves.
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do i=-ia2,ia2
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freq=nfqso + i*df
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write(17,1100) freq,ccf1(i),xdt,ccf2(i)
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1100 format(4f10.3)
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enddo
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close(17)
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900 return
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end subroutine q65_dec0
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subroutine q65_clravg
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if(allocated(s1a)) s1a=0.
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navg=0
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return
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end subroutine q65_clravg
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subroutine q65_symspec(iwave,nmax,iz,jz,s1)
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integer*2 iwave(0:nmax-1) !Raw data
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real s1(iz,jz)
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complex, allocatable :: c0(:) !Complex spectrum of symbol
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allocate(c0(0:nsps-1))
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nfft=nsps
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fac=1/32767.0
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do j=1,jz !Compute symbol spectra at step size
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i1=(j-1)*istep
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i2=i1+nsps-1
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k=-1
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do i=i1,i2,2 !Load iwave data into complex array c0, for r2c FFT
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xx=iwave(i)
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yy=iwave(i+1)
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k=k+1
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c0(k)=fac*cmplx(xx,yy)
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enddo
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c0(k+1:)=0.
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call four2a(c0,nfft,1,-1,0) !r2c FFT
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do i=1,iz
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s1(i,j)=real(c0(i))**2 + aimag(c0(i))**2
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enddo
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! For large Doppler spreads, should we smooth the spectra here?
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do i=1,nsmo
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call smo121(s1(1:iz,j),iz)
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enddo
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enddo
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s1a=s1a+s1
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navg=navg+1
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return
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end subroutine q65_symspec
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subroutine q65_dec_q3(s1,iz,jz,s3,LL,ipk,jpk,snr2,dat4,idec,decoded)
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character*37 decoded
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integer dat4(13)
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real s1(iz,jz)
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real s3(-64:LL-65,63)
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i1=i0+ipk-64
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i2=i1+LL-1
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j=j0+jpk-7
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n=0
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do k=1,85
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j=j+8
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if(sync(k).gt.0.0) then
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cycle
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endif
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n=n+1
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if(j.ge.1 .and. j.le.jz) then
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do i=0,LL-1
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s3(i-64,n)=s1(i+i1,j) !Copy from s1 into s3
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enddo
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endif
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enddo
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nsubmode=0
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if(mode_q65.eq.2) nsubmode=1
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if(mode_q65.eq.4) nsubmode=2
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if(mode_q65.eq.8) nsubmode=3
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if(mode_q65.eq.16) nsubmode=4
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baud=12000.0/nsps
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do ibw=ibwa,ibwb
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b90=1.72**ibw
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b90ts=b90/baud
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call q65_dec1(s3,nsubmode,b90ts,esnodb,irc,dat4,decoded)
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if(irc.ge.0) then
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snr2=esnodb - db(2500.0/baud) + 3.0 !Empirical adjustment
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idec=3
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exit
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endif
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enddo
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return
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end subroutine q65_dec_q3
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subroutine q65_q3a(xdt,f0,nfqso,nsps,snr2,dat4,idec,decoded)
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integer dat4(13)
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character*37 decoded
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real, allocatable :: s3a(:,:) !Symbol energies for avg s3a(LL,63)
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df=12000.0/nsps
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dtstep=float(nsps)/(NSTEP*12000.0)
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iz=5000.0/df !Uppermost frequency bin, at 5000 Hz
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txt=85.0*nsps/12000.0
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istep=nsps/NSTEP
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jz=(txt+1.0)*12000.0/istep !Number of symbol/NSTEP bins
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LL=64*(2+mode_q65)
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allocate(s3a(-64:LL-65,63))
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ipk=nint((f0-nfqso)/df) + mode_q65
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jpk=nint(xdt/dtstep)
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call q65_dec_q3(s1a,iz,jz,s3a,LL,ipk,jpk,snr2,dat4,idec,decoded)
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return
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end subroutine q65_q3a
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subroutine q65_ccf_85(s1,iz,jz,nfqso,ia,ia2, &
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ipk,jpk,f0,xdt,imsg_best,ccf,ccf1)
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real s1(iz,jz)
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real ccf(-ia2:ia2,-53:214)
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real ccf1(-ia2:ia2)
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integer ijpk(2)
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integer itone(85)
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ipk=0
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jpk=0
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ccf_best=0.
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imsg_best=-1
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do imsg=1,ncw
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i=1
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k=0
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do j=1,85
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if(j.eq.isync(i)) then
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i=i+1
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itone(j)=-1
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else
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k=k+1
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itone(j)=codewords(k,imsg)
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endif
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enddo
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! Compute 2D ccf using all 85 symbols in the list message
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ccf=0.
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iia=200.0/df
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do lag=lag1,lag2
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do k=1,85
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j=j0 + NSTEP*(k-1) + 1 + lag
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if(j.ge.1 .and. j.le.jz) then
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do i=-ia2,ia2
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ii=i0+mode_q65*itone(k)+i
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if(ii.ge.iia .and. ii.le.iz) ccf(i,lag)=ccf(i,lag) + s1(ii,j)
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enddo
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endif
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enddo
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enddo
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ccfmax=maxval(ccf(-ia:ia,:))
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if(ccfmax.gt.ccf_best) then
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ccf_best=ccfmax
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ijpk=maxloc(ccf(-ia:ia,:))
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ipk=ijpk(1)-ia-1
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jpk=ijpk(2)-53-1
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f0=nfqso + (ipk-mode_q65)*df
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xdt=jpk*dtstep
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imsg_best=imsg
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ccf1=ccf(:,jpk)
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endif
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enddo ! imsg
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return
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end subroutine q65_ccf_85
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subroutine q65_ccf_22(s1,iz,jz,nfqso,ia,ia2,ipk,jpk,f0,xdt,ccf,ccf2)
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real s1(iz,jz)
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real ccf(-ia2:ia2,-53:214)
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real ccf2(-ia2:ia2)
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integer ijpk(2)
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ccf=0.
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do lag=lag1,lag2
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do k=1,85
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n=NSTEP*(k-1) + 1
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j=n+lag+j0
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if(j.ge.1 .and. j.le.jz) then
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do i=-ia2,ia2
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if(i0+i.lt.1 .or. i0+i.gt.iz) cycle
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ccf(i,lag)=ccf(i,lag) + sync(k)*s1(i0+i,j)
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enddo
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endif
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enddo
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enddo
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do i=-ia2,ia2
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ccf2(i)=maxval(ccf(i,:))
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enddo
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ijpk=maxloc(ccf(-ia:ia,:))
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ipk=ijpk(1)-ia-1
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jpk=ijpk(2)-53-1
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f0=nfqso + ipk*df
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xdt=jpk*dtstep
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return
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end subroutine q65_ccf_22
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subroutine q65_dec1(s3,nsubmode,b90ts,esnodb,irc,dat4,decoded)
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use packjt77
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real s3(1,1) !Silence compiler warning that wants to see a 2D array
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real s3prob(0:63,63) !Symbol-value probabilities
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integer dat4(13)
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character c77*77,decoded*37
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logical unpk77_success
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nFadingModel=1
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decoded=' '
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call q65_intrinsics_ff(s3,nsubmode,b90ts,nFadingModel,s3prob)
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call q65_dec_fullaplist(s3,s3prob,codewords,ncw,esnodb,dat4,plog,irc)
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if(sum(dat4).le.0) irc=-2
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if(irc.ge.0 .and. plog.gt.PLOG_MIN) then
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write(c77,1000) dat4(1:12),dat4(13)/2
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1000 format(12b6.6,b5.5)
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call unpack77(c77,0,decoded,unpk77_success) !Unpack to get msgsent
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else
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irc=-1
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endif
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return
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end subroutine q65_dec1
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subroutine q65_dec2(s3,nsubmode,b90ts,esnodb,irc,dat4,decoded)
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use packjt77
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real s3(1,1) !Silence compiler warning that wants to see a 2D array
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real s3prob(0:63,63) !Symbol-value probabilities
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integer dat4(13)
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character c77*77,decoded*37
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logical unpk77_success
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nFadingModel=1
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decoded=' '
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call q65_intrinsics_ff(s3,nsubmode,b90ts,nFadingModel,s3prob)
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call q65_dec(s3,s3prob,APmask,APsymbols,esnodb,dat4,irc)
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if(sum(dat4).le.0) irc=-2
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if(irc.ge.0) then
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write(c77,1000) dat4(1:12),dat4(13)/2
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1000 format(12b6.6,b5.5)
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call unpack77(c77,0,decoded,unpk77_success) !Unpack to get msgsent
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endif
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return
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end subroutine q65_dec2
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subroutine q65_s1_to_s3(s1,iz,jz,ipk,jpk,LL,mode_q65,sync,s3)
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! Copy from s1 or s1a into s3
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real s1(iz,jz)
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real s3(-64:LL-65,63)
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real sync(85) !sync vector
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i1=i0+ipk-64 + mode_q65
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i2=i1+LL-1
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if(i1.ge.1 .and. i2.le.iz) then
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j=j0+jpk-7
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n=0
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do k=1,85
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j=j+8
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if(sync(k).gt.0.0) then
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cycle
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endif
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n=n+1
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if(j.ge.1 .and. j.le.jz) s3(-64:LL-65,n)=s1(i1:i2,j)
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enddo
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endif
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return
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end subroutine q65_s1_to_s3
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end module q65
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