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5ecaab899d
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6962 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
45 lines
1.3 KiB
Fortran
45 lines
1.3 KiB
Fortran
subroutine spec64(c0,npts2,mode64,jpk,s3a)
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parameter (NSPS=2304) !Samples per symbol at 4000 Hz
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complex c0(0:360000) !Complex spectrum of dd()
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complex cs(0:NSPS-1) !Complex symbol spectrum
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real s3a(0:63,1:63) !Synchronized symbol spectra
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nfft4=221184
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c0(npts2:)=0.
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call four2a(c0,nfft4,1,-1,1) !Forward c2c
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ndown=16/mode64
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nfft5=nfft4/ndown
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npts3=npts2/ndown
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call four2a(c0,nfft5,1,1,1) !Inverse c2c, downsampled
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nfft6=nsps/ndown
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fsample=4000.0/ndown
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df=fsample/nfft6
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jpkd=nint(float(jpk)/ndown)
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do j=1,63
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jj=j+7 !Skip first Costas array
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if(j.ge.32) jj=j+14 !Skip middle Costas array
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ja=jpkd + (jj-1)*nfft6
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jb=ja+nfft6-1
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cs(0:nfft6-1)=1.3e-8*c0(ja:jb)
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call four2a(cs,nfft6,1,-1,1)
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ia=-mode64/2 - mode64
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do ii=0,63
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ia=ia+mode64
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ib=ia+mode64-1
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s=0.
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do i=ia,ib
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if(i.ge.0) then
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s=s + real(cs(i))**2 + aimag(cs(i))**2
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else
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s=s + real(cs(nfft6+i))**2 + aimag(cs(nfft6+i))**2
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endif
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enddo
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s3a(ii,j)=s/mode64
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enddo
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enddo
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return
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end subroutine spec64
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