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FT8 now uses nsps=1920.

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git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7784 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Joe Taylor 2017-07-06 13:38:06 +00:00
parent 52d8324382
commit 76d1169140
7 changed files with 20 additions and 16 deletions
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7
lib/fsk4hf/ft8_downsample.f90
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@ -1,9 +1,10 @@
subroutine ft8_downsample(dd,newdat,f0,c1)
! Downconvert to complex data sampled at 187.5 Hz, 32 samples/symbol
! Downconvert to complex data sampled at 200 Hz ==> 32 samples/symbol
parameter (NMAX=15*12000)
parameter (NFFT1=200000,NFFT2=3125) !200000/64 = 3125
parameter (NFFT1=192000,NFFT2=3200) !192000/60 = 3200
logical newdat
complex c1(0:NFFT2-1)
complex cx(0:NFFT1/2)
@ -20,7 +21,7 @@ subroutine ft8_downsample(dd,newdat,f0,c1)
endif
df=12000.0/NFFT1
baud=12000.0/2048.0
baud=12000.0/1920.0
i0=nint(f0/df)
ft=f0+8.0*baud
it=min(nint(ft/df),NFFT1/2)

4
lib/fsk4hf/ft8_params.f90
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@ -3,8 +3,8 @@ parameter (KK=87) !Information bits (75 + CRC12)
parameter (ND=58) !Data symbols
parameter (NS=21) !Sync symbols (3 @ Costas 7x7)
parameter (NN=NS+ND) !Total channel symbols (79)
parameter (NSPS=2048) !Samples per symbol at 12000 S/s
parameter (NZ=NSPS*NN) !Samples in full 15 s waveform (161,792)
parameter (NSPS=1920) !Samples per symbol at 12000 S/s
parameter (NZ=NSPS*NN) !Samples in full 15 s waveform (151,680)
parameter (NMAX=15*12000) !Samples in iwave (180,000)
parameter (NFFT1=2*NSPS, NH1=NFFT1/2) !Length of FFTs for symbol spectra
parameter (NHSYM=2*NMAX/NH1-1) !Number of symbol spectra (1/2-symbol steps)

4
lib/fsk4hf/ft8b.f90
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@ -12,14 +12,14 @@ subroutine ft8b(dd0,newdat,nfqso,f1,xdt,nharderrors,dmin,nbadcrc,message,xsnr)
real dd0(15*12000)
integer*1 decoded(KK),apmask(3*ND),cw(3*ND)
integer itone(NN)
complex cd0(3125)
complex cd0(3200)
complex ctwk(32)
complex csymb(32)
logical newdat
max_iterations=40
norder=2
fs2=12000.0/64.0
fs2=12000.0/60.0
dt2=1.0/fs2
twopi=8.0*atan(1.0)
delfbest=0.

3
lib/fsk4hf/ft8sim.f90
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@ -52,12 +52,11 @@ program ft8sim
! call sgran()
c=0.
do ifile=1,nfiles
c0=0.
do isig=1,25
f0=(isig+2)*100.0
phi=0.0
k=-1 + nint(xdt/dt)
k=-1 + nint(xdt+0.5/dt)
do j=1,NN !Generate complex waveform
dphi=twopi*(f0+itone(j)*baud)*dt
if(k.eq.0) phi=-dphi

12
lib/fsk4hf/sync8.f90
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@ -1,7 +1,7 @@
subroutine sync8(iwave,nfa,nfb,nfqso,s,candidate,ncand)
include 'ft8_params.f90'
parameter (JZ=35) !DT up to +/- 3 s
parameter (JZ=31) !DT up to +/- 2.5 s
complex cx(0:NH1)
real s(NH1,NHSYM)
real savg(NH1)
@ -20,9 +20,9 @@ subroutine sync8(iwave,nfa,nfb,nfqso,s,candidate,ncand)
! Compute symbol spectra at half-symbol steps.
savg=0.
istep=NSPS/2 !1024
tstep=istep/12000.0 !0.085333 s
df=12000.0/NFFT1 !2.93 Hz
istep=NSPS/2 !960
tstep=istep/12000.0 !0.08 s
df=12000.0/NFFT1 !3.125 Hz
! Compute symbol spectra at half-symbol steps
fac=1.0/300.0
@ -38,6 +38,10 @@ subroutine sync8(iwave,nfa,nfb,nfqso,s,candidate,ncand)
savg=savg + s(1:NH1,j) !Average spectrum
enddo
savg=savg/NHSYM
! do i=1,NH1
! write(51,3051) i*df,savg(i),db(savg(i))
!3051 format(f10.3,e12.3,f12.3)
! enddo
ia=max(1,nint(nfa/df))
ib=nint(nfb/df)

4
lib/fsk4hf/sync8d.f90
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@ -19,10 +19,10 @@ subroutine sync8d(cd0,i0,ctwk,itwk,sync)
! Set some constants and compute the csync array.
if( first ) then
twopi=8.0*atan(1.0)
fs2=12000.0/64.0 !Sample rate after downsampling
fs2=12000.0/60.0 !Sample rate after downsampling
dt2=1/fs2 !Corresponding sample interval
taus=32*dt2 !Symbol duration
baud=1/taus !Keying rate
baud=1.0/taus !Keying rate
do i=0,6
phi=0.0
dphi=twopi*icos7(i)*baud*dt2

2
lib/ft8_decode.f90
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@ -64,7 +64,7 @@ contains
f1,nbadcrc,message)
! write(*,'(f7.2,i5,f7.2,f9.1,i5,f7.2,2x,a22)') sync,nsnr,xdt,f1,nharderrors,dmin,message
! write(13,1110) datetime,0,nsnr,xdt,f1,nharderrors,dmin,message
1110 format(a13,2i4,f6.2,f7.1,i4,' ~ ',f6.2,2x,a22,' FT8')
!1110 format(a13,2i4,f6.2,f7.1,i4,' ~ ',f6.2,2x,a22,' FT8')
! write(51,3051) xdt,f1,sync,dmin,nsnr,nharderrors,nbadcrc,message
!3051 format(4f9.1,3i5,2x,a22)
! flush(51)