82 lines
2.3 KiB
Plaintext
82 lines
2.3 KiB
Plaintext
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subroutine msksoftsym(zz,aa,bb,id,nterms,ierror,rxdata,nhard0,nhardsync0)
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parameter (KK=84) !Information bits (72 + CRC12)
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parameter (ND=168) !Data symbols: LDPC (168,84), r=1/2
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parameter (NS=65) !Sync symbols (2 x 26 + Barker 13)
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parameter (NR=3) !Ramp up/down
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parameter (NN=NR+NS+ND) !Total symbols (236)
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parameter (NSPS=16) !Samples per MSK symbol (16)
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parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
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parameter (N13=13*N2) !Samples in central sync vector (416)
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parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760)
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parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
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complex zz(NS+ND) !Complex symbol values (intermediate)
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complex z,z0
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real rxdata(ND) !Soft symbols
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real aa(20),bb(20) !Fitted polyco's
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integer id(NS+ND) !NRZ values (+/-1) for Sync and Data
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integer ierror(NS+ND)
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n=0
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ierror=0
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do j=1,117
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xx=j*2.0/117.0 - 1.0
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yii=1.
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yqq=0.
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if(nterms.gt.0) then
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yii=aa(1)
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yqq=bb(1)
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do i=2,nterms
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yii=yii + aa(i)*xx**(i-1)
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yqq=yqq + bb(i)*xx**(i-1)
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enddo
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endif
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z0=cmplx(yii,yqq)
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z=zz(j)*conjg(z0)
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p=real(z)
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if(abs(id(j)).eq.2) then
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if(real(z)*id(j).lt.0) then !Sync bit
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nhardsync0=nhardsync0+1
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ierror(j)=2
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endif
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else
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n=n+1 !Data bit
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rxdata(n)=p
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ierr=0
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if(id(j)*p.lt.0) then
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ierr=1
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ierror(j)=1
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endif
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nhard0=nhard0+ierr
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endif
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enddo
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do j=118,233
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xx=(j-116.5)*2.0/117.0 - 1.0
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yii=1.
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yqq=0.
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if(nterms.gt.0) then
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yii=aa(1)
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yqq=bb(1)
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do i=2,nterms
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yii=yii + aa(i)*xx**(i-1)
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yqq=yqq + bb(i)*xx**(i-1)
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enddo
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endif
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z0=cmplx(yii,yqq)
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z=zz(j)*conjg(z0)
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p=aimag(z)
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n=n+1
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rxdata(n)=p
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ierr=0
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if(id(j)*p.lt.0) then
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ierr=1
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ierror(j)=1
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endif
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nhard0=nhard0+ierr
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enddo
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return
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end subroutine msksoftsym
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