15bf364e5e
commit dbca224ee15f598ba86b860c19e902b594f6b888
Author: Jordan Sherer <jordan@widefido.com>
Date: Wed Aug 14 21:10:17 2019 -0400
Cleanup decoder with easy parameters
commit 427a6ac6bf02a7de80e76b921bbd48ec23dab0c4
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 22:56:32 2019 -0400
Working on downsampling
commit ef5e1fb9cdafb6069b6f67377c3bc9e073d2785e
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 22:01:34 2019 -0400
Fixed NN parameters
commit 216dbc83a931127540fb028d3365a205b4ef1d28
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 21:40:20 2019 -0400
Fixed dupe during sync
commit 9505d50ba6c42b05e5fff1a059864a643d9e7558
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 16:54:37 2019 -0400
Tweaking downsampling
commit 86cd07e1ac8ce8d64cdd2d4321cf295cd867f80e
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 10:11:07 2019 -0400
Working with logging
commit 0de3849a442d20081f545c6fef5fadf2def6e0d2
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 03:46:51 2019 -0400
250 millisecond startup delay
commit a35cc5302b6f8532a424d504a4e2feaacf74ef99
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 03:39:20 2019 -0400
1200 sps, 10 seconds, 80Hz
commit 6f36db20f90c510336b497605d9d7667d6f0f44f
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 03:27:12 2019 -0400
Working word count
commit 741c55ac0840512d68e1fbdb2f1fff6adfcd4612
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 02:40:40 2019 -0400
Updated LDPC simulator
commit ce0992644315402503f44bdae4131bacf2cc3e21
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 02:34:01 2019 -0400
Weird. Apparently symbol stop is the only way to get decodes to work in app...need to figure out why
commit 8b330fbff6574f2ee6d7a471dd93a2cb57b492dd
Author: Jordan Sherer <jordan@widefido.com>
Date: Tue Aug 13 01:50:37 2019 -0400
More parameter fixups (downsampling) and first decode
commit 37c780b45e6579294b5a4692b8e8d0602d9bd8b1
Author: Jordan Sherer <jordan@widefido.com>
Date: Mon Aug 12 23:20:58 2019 -0400
More params fixing
commit bc8547e1e8f55bfb4bce5f95890f3cf6798e36d7
Author: Jordan Sherer <jordan@widefido.com>
Date: Mon Aug 12 22:48:00 2019 -0400
Fixed params in fortran code
commit 10fbf9f4a78c6244e0082a31819ee26aeae39325
Author: Jordan Sherer <jordan@widefido.com>
Date: Mon Aug 12 16:08:32 2019 -0400
Using constants in place of literals in a few places to make it easier to change
55 lines
1.3 KiB
Fortran
55 lines
1.3 KiB
Fortran
subroutine ft8_downsample(dd,newdat,f0,c1)
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! Downconvert to complex data sampled at 200 Hz ==> 32 samples/symbol
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include 'ft8_params.f90'
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parameter (NDFFT1=NSPS*NDD, NDFFT2=NDFFT1/NDOWN) ! Downconverted FFT Size - 192000/60 = 3200
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logical newdat,first
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complex c1(0:NDFFT2-1)
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complex cx(0:NDFFT1/2)
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real dd(NMAX),x(NDFFT1),taper(0:NDD)
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equivalence (x,cx)
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data first/.true./
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save cx,first,taper
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if(first) then
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pi=4.0*atan(1.0)
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do i=0,NDD
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taper(i)=0.5*(1.0+cos(i*pi/NDD))
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enddo
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first=.false.
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endif
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if(newdat) then
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! Data in dd have changed, recompute the long FFT
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x(1:NMAX)=dd
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x(NMAX+1:NDFFT1)=0. !Zero-pad the x array
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call four2a(cx,NDFFT1,1,-1,0) !r2c FFT to freq domain
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newdat=.false.
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endif
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df=12000.0/NDFFT1
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baud=12000.0/NSPS
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i0=nint(f0/df)
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ft=f0+8.5*baud
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it=min(nint(ft/df),NDFFT1/2)
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fb=f0-1.5*baud
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ib=max(1,nint(fb/df))
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k=0
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c1=0.
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do i=ib,it
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c1(k)=cx(i)
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k=k+1
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enddo
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c1(0:NDD)=c1(0:NDD)*taper(NDD:0:-1)
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c1(k-1-NDD:k-1)=c1(k-1-NDD:k-1)*taper
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c1=cshift(c1,i0-ib)
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call four2a(c1,NDFFT2,1,1,1) !c2c FFT back to time domain
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fac=1.0/sqrt(float(NDFFT1)*NDFFT2)
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c1=fac*c1
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return
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end subroutine ft8_downsample
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