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WSJT-X
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Code cleanup and improvement in the JT4 decoder. 

NB: should remove the present downsampling to 11025/2 Hz, which unnecessarily
limits the availabler range of Fx Freq ("nfqso" in the source code).
This commit is contained in:
Joe Taylor 2018-07-23 12:42:50 -04:00
parent 59f713ba76
commit 7ff366abe3
5 changed files with 59 additions and 119 deletions
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12
lib/jt49sim.f90
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@ -9,7 +9,7 @@ program jt49sim
parameter (NFFT=10*65536,NH=NFFT/2)
type(hdr) h !Header for .wav file
integer*2 iwave(NMAX) !Generated waveform
integer*4 itone(206) !Channel symbols (values 0-8)
integer*4 itone(206) !Channel symbols (values 0-8)
real*4 xnoise(NMAX) !Generated random noise
real*4 dat(NMAX) !Generated real data
complex cdat(NMAX) !Generated complex waveform
@ -22,10 +22,12 @@ program jt49sim
nargs=iargc()
if(nargs.ne. 7) then
print *, 'Usage: jt49sim "msg" nA-nE Nsigs fDop DT Nfiles SNR'
print *, 'Example jt49sim "K1ABC W9XYZ EN37" 4G 10 0.2 0.0 1 0'
print *, 'Example jt49sim "K1ABC W9XYZ EN37" 9A 1 0.0 0.0 1 -20'
print *, 'Example: jt49sim "K1ABC W9XYZ EN37" 4G 10 0.2 0.0 1 0'
print *, 'Example: jt49sim "K1ABC W9XYZ EN37" 9A 1 0.0 0.0 1 -20'
print *, 'Use msg=@nnnn to generate a tone at nnnn Hz:'
print *, 'Example jt49sim "@1500" 9A 1 10.0 0.0 1 -20'
print *, 'Example: jt49sim "@1500" 9A 1 10.0 0.0 1 -20'
print *, 'If Nsigs > 100, generate one signal with f0=Nsigs'
print *, 'Example: jt49sim "K1ABC W9XYZ EN37" 4F 1800 0.2 0.0 1 -20'
go to 999
endif
call getarg(1,message)
@ -84,6 +86,7 @@ program jt49sim
if(mod(nsigs,2).eq.0) f0=1500.0 + dfsig*(isig-0.5-nsigs/2)
if(mod(nsigs,2).eq.1) f0=1500.0 + dfsig*(isig-(nsigs+1)/2)
if(nsigs.eq.1) f0=1000.0
if(nsigs.gt.100) f0=nsigs
xsnr=snrdb
if(snrdb.eq.0.0) xsnr=-20 - isig
@ -121,6 +124,7 @@ program jt49sim
k=k+1
if(k.ge.1) cdat(k)=cdat(k) + sig*z
enddo
if(nsigs.gt.100) exit
enddo
if(fspread.ne.0) then !Apply specified Doppler spread

15
lib/jt4_decode.f90
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@ -111,12 +111,6 @@ contains
character(len=12), intent(in) :: mycall,hiscall
character(len=6), intent(in) :: hisgrid
real, intent(in) :: dat(npts) !Raw data
real ccfblue(-5:540) !CCF in time
real ccfred(-224:224) !CCF in frequency
real ps0(450)
! real z(458,65)
logical first,prtavg
character decoded*22,special*5
character*22 avemsg,deepmsg,deepave,blank,deepmsg0,deepave1
@ -128,8 +122,6 @@ contains
nsave=0
first=.false.
blank=' '
ccfblue=0.
ccfred=0.
! Silence compiler warnings
if(dttol.eq.-99.0 .and. emedelay.eq.-99.0 .and. nagain) stop
endif
@ -157,12 +149,11 @@ contains
! Attempt to synchronize: look for sync pattern, get DF and DT.
call timer('sync4 ',0)
mousedf=nint(nfqso + 1.5*4.375*mode4 - 1270.46)
call sync4(dat,npts,ntol,1,MouseDF,4,mode4,minw+1,dtx,dfx, &
snrx,snrsync,ccfblue,ccfred,flip,width,ps0)
call sync4(dat,npts,ntol,nfqso,4,mode4,minw+1,dtx,dfx, &
snrx,snrsync,flip,width)
sync=snrsync
dtxz=dtx-0.8
nfreqz=dfx + 1270.46 - 1.5*4.375*mode4
nfreqz=nint(dfx)
call timer('sync4 ',1)
nsnr=nint(snrx)

2
lib/stdmsg.f90
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@ -37,7 +37,7 @@ function stdmsg(msg0)
call packmsg(msg0,dat,itype)
call unpackmsg(dat,msg)
msg(23:37)=' '
stdmsg=(msg.eq.msg1) .and. (itype.ge.0) .and. itype.ne.6
stdmsg=(msg(1:22).eq.msg1(1:22)) .and. (itype.ge.0) .and. (itype.ne.6)
if(.not.stdmsg) then
call parse77(msg1,i3,n3)
if(i3.gt.0 .or. n3.gt.0) stdmsg=.true.

138
lib/sync4.f90
View File

@ -1,5 +1,5 @@
subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
dtx,dfx,snrx,snrsync,ccfblue,ccfred1,flip,width,ps0)
subroutine sync4(dat,jz,ntol,nfqso,mode,mode4,minwidth,dtx,dfx,snrx, &
snrsync,flip,width)
! Synchronizes JT4 data, finding the best-fit DT and DF.
@ -8,14 +8,10 @@ subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
parameter (NSMAX=525) !Max number of half-symbol steps
integer ntol !Range of DF search
real dat(jz)
real psavg(NHMAX) !Average spectrum of whole record
real ps0(450) !Avg spectrum for plotting
real s2(NHMAX,NSMAX) !2d spectrum, stepped by half-symbols
real ccfblue(-5:540) !CCF with pseudorandom sequence
real ccfred(-450:450) !Peak of ccfblue, as function of freq
real red(-450:450) !Peak of ccfblue, as function of freq
real ccfred1(-224:224) !Peak of ccfblue, as function of freq
real tmp(1260)
real ccfred(NHMAX) !Peak of ccfblue, as function of freq
real red(NHMAX) !Peak of ccfblue, as function of freq
integer ipk1(1)
integer nch(7)
logical savered
@ -23,8 +19,6 @@ subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
data nch/1,2,4,9,18,36,72/
save
! Do FFTs of twice symbol length, stepped by half symbols. Note that
! we have already downsampled the data by factor of 2.
nsym=207
@ -33,66 +27,50 @@ subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
nq=nfft/4
nsteps=jz/nq - 1
df=0.5*11025.0/nfft
psavg(1:nh)=0.
ftop=nfqso + 7*mode4*df
if(ftop.gt.11025.0/4.0) then
print*,'*** Rx Freq is set too high for this sybmode ***'
go to 900
endif
if(mode.eq.-999) width=0. !Silence compiler warning
do j=1,nsteps !Compute spectrum for each step, get average
k=(j-1)*nq + 1
call ps4(dat(k),nfft,s2(1,j))
psavg(1:nh)=psavg(1:nh) + s2(1:nh,j)
enddo
nsmo=min(10*mode4,150)
call flat1b(psavg,nsmo,s2,nh,nsteps,NHMAX,NSMAX) !Flatten spectra
if(mode4.ge.9) call smo(psavg,nh,tmp,mode4/4)
i0=132
do i=1,450
ps0(i)=5.0*(psavg(i0+2*i) + psavg(i0+2*i+1) - 2.0)
enddo
! Set freq and lag ranges
famin=200.0 + 3*mode4*df
fbmax=2700.0 - 3*mode4*df
fa=famin
fb=fbmax
if(NFreeze.eq.1) then
fa=max(famin,1270.46+MouseDF-ntol)
fb=min(fbmax,1270.46+MouseDF+ntol)
else
fa=max(famin,1270.46+MouseDF-600)
fb=min(fbmax,1270.46+MouseDF+600)
endif
ia=fa/df - 3*mode4 !Index of lowest tone, bottom of range
ib=fb/df - 3*mode4 !Index of lowest tone, top of range
i0=nint(1270.46/df)
irange=450
if(ia-i0.lt.-irange) ia=i0-irange
if(ib-i0.gt.irange) ib=i0+irange
ia=(nfqso-ntol)/df !Index of lowest tone, bottom of search range
ib=(nfqso+ntol)/df !Index of lowest tone, top of search range
iamin=nint(100.0/df)
if(ia.lt.iamin) ia=iamin
ibmax=nint(2700.0/df) - 6*mode4
if(ib.gt.ibmax) ib=ibmax
lag1=-5
lag2=59
syncbest=-1.e30
snrx=-26.0
ccfred=0.
jmax=-1000
jmin=1000
red=0.
i0=nint(nfqso/df)
do ich=minwidth,7 !Find best width
kz=nch(ich)/2
savered=.false.
do i=ia+kz,ib-kz !Find best frequency channel for CCF
iaa=ia+kz
ibb=ib-kz
do i=iaa,ibb !Find best frequency channel for CCF
call xcor4(s2,i,nsteps,nsym,lag1,lag2,ich,mode4,ccfblue,ccf0, &
lagpk0,flip)
j=i-i0 + 3*mode4
if(j.ge.-372 .and. j.le.372) then
ccfred(j)=ccf0
jmax=max(j,jmax)
jmin=min(j,jmin)
endif
ccfred(i)=ccf0
! Find rms of the CCF, without main peak
call slope(ccfblue(lag1),lag2-lag1+1,lagpk0-lag1+1.0)
sync=abs(ccfblue(lagpk0))
! write(*,3000) ich,i,i*df,ccf0,sync,syncbest
!3000 format(2i5,4f12.3)
! Find best sync value
if(sync.gt.syncbest*1.03) then
@ -105,10 +83,12 @@ subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
enddo
if(savered) red=ccfred
enddo
if(syncbest.lt.-1.e29) go to 900
ccfred=red
call pctile(ccfred(iaa:ibb),ibb-iaa+1,45,base)
ccfred=ccfred-base
! width=df*nch(ichpk)
dfx=(ipk-i0 + 3*mode4)*df
dfx=ipk*df
! Peak up in time, at best whole-channel frequency
call xcor4(s2,ipk,nsteps,nsym,lag1,lag2,ichpk,mode4,ccfblue,ccfmax, &
@ -131,60 +111,36 @@ subroutine sync4(dat,jz,ntol,NFreeze,MouseDF,mode,mode4,minwidth, &
enddo
rms=sqrt(sq/nsq)
snrsync=max(0.0,db(abs(ccfblue(lagpk)/rms - 1.0)) - 4.5)
snrx=-26.
if(mode4.eq.2) snrx=-25.
if(mode4.eq.4) snrx=-24.
if(mode4.eq.9) snrx=-23.
if(mode4.eq.18) snrx=-22.
if(mode4.eq.36) snrx=-21.
if(mode4.eq.72) snrx=-20.
snrx=snrx + snrsync
dt=2.0/11025.0
istart=xlag*nq
dtx=istart*dt
ccfred1=0.
jmin=max(jmin,-224)
jmax=min(jmax,224)
do i=jmin,jmax
ccfred1(i)=ccfred(i)
enddo
ipk1=maxloc(ccfred1) - 225
ns=0
s=0.
iw=min(mode4,(ib-ia)/4)
do i=jmin,jmax
if(abs(i-ipk1a).gt.iw) then
s=s+ccfred1(i)
ns=ns+1
endif
enddo
base=s/ns
ccfred1=ccfred1-base
ccf10=0.5*maxval(ccfred1)
do i=ipk1a,jmin,-1
if(ccfred1(i).le.ccf10) exit
ipk1=maxloc(ccfred)
ccf10=0.5*maxval(ccfred)
do i=ipk1a,ia,-1
if(ccfred(i).le.ccf10) exit
enddo
i1=i
do i=ipk1a,jmax
if(ccfred1(i).le.ccf10) exit
do i=ipk1a,ib
if(ccfred(i).le.ccf10) exit
enddo
nw=i-il
nw=i-i1
width=nw*df
sq=0.
ns=0
do j=jmin,jmax
if(abs(j-ipk1a).lt.nw) then
sq=sq + ccfred1(j)*ccfred1(j)
iaa=max(ipk1a-10*nw,ia)
ibb=min(ipk1a+10*nw,ib)
jmax=2*mode4/3
do i=iaa,ibb
j=abs(i-ipk1a)
if(j.gt.nw .and. j.lt.jmax) then
sq=sq + ccfred(j)*ccfred(j)
ns=ns+1
endif
enddo
rms=sqrt(sq/ns)
snrx=10.0*log10(ccfred1(ipk1a)) - 26.0
snrx=10.0*log10(ccfred(ipk1a)/rms) - 41.2
return
900 return
end subroutine sync4
include 'flat1b.f90'

11
mainwindow.cpp
View File

@ -2826,17 +2826,6 @@ void MainWindow::readFromStdout() //readFromStdout
{
while(proc_jt9.canReadLine()) {
QByteArray t=proc_jt9.readLine();
/*
if(m_mode=="FT8" and !m_config.bHound() and t.contains(";")) {
if(t.contains("<...>")) continue;
if(!m_bWarnedHound) {
QString errorMsg;
MessageBox::critical_message (this,
tr("Should you be in \"FT8 DXpedition Hound\" mode?"), errorMsg);
m_bWarnedHound=true;
}
}
*/
// qint64 ms=QDateTime::currentMSecsSinceEpoch() - m_msec0;
bool bAvgMsg=false;
int navg=0;