mirror of https://github.com/saitohirga/WSJT-X.git
37 lines
946 B
Fortran
37 lines
946 B
Fortran
subroutine genfsk4(id,f00,nts,c)
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parameter (ND=60) !Data symbols: LDPC (120,60), r=1/2
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parameter (NN=ND) !Total symbols (60)
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parameter (NSPS=57600) !Samples per symbol at 12000 sps
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parameter (NZ=NSPS*NN) !Samples in waveform (3456000)
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parameter (NFFT=NZ) !Full length FFT
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complex c(0:NFFT-1) !Complex waveform
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real*8 twopi,dt,fs,baud,f0,dphi,phi
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integer id(NN) !Encoded 2-bit data (values 0-3)
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f0=f00
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twopi=8.d0*atan(1.d0)
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fs=12000.d0
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dt=1.0/fs
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baud=1.d0/(NSPS*dt)
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! Generate the 4-FSK waveform
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x=0.
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c=0.
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phi=0.d0
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k=-1
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do j=1,NN
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dphi=twopi*(f0 + nts*id(j)*baud)*dt
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do i=1,NSPS
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k=k+1
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phi=phi+dphi
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if(phi.gt.twopi) phi=phi-twopi
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xphi=phi
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c(k)=cmplx(cos(xphi),sin(xphi))
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enddo
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enddo
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return
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end subroutine genfsk4
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