mirror of https://github.com/saitohirga/WSJT-X.git
36 lines
998 B
Fortran
36 lines
998 B
Fortran
subroutine spec4(c,s,savg)
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parameter (KK=84) !Information bits (72 + CRC12)
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parameter (ND=84) !Data symbols: LDPC (168,84), r=1/2
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parameter (NS=12) !Sync symbols (3 @ 4x4 Costas arrays)
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parameter (NR=2) !Ramp up/down
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parameter (NN=NR+NS+ND) !Total symbols (98)
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parameter (NSPS=2688/84) !Samples per symbol (32)
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parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760)
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parameter (NFFT=2*NSPS,NH=NSPS)
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complex c(0:NZ-1)
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complex c1(0:NFFT-1)
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real s(0:NH,NN)
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real savg(0:NH)
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fs=12000.0/84.0
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df=fs/NFFT
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savg=0.
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do j=1,NN
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ia=(j-1)*NSPS
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ib=ia + NSPS-1
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c1(0:NSPS-1)=c(ia:ib)
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c1(NSPS:)=0.
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call four2a(c1,NFFT,1,-1,1)
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do k=1,NSPS
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s(k,j)=real(c1(k))**2 + aimag(c1(k))**2
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enddo
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savg=savg+s(0:NH,j)
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enddo
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s=s/NZ
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savg=savg/(NN*NZ)
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return
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end subroutine spec4
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