WSJT-X/lib/qra64a.f90
Joe Taylor 72dfe01bf3 Working on QRA64 sync, snr estimates, etc., for QRA64 decoder.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7321 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2016-11-15 21:39:55 +00:00

141 lines
4.0 KiB
Fortran

subroutine qra64a(dd,npts,nutc,nf1,nf2,nfqso,ntol,mode64,minsync,mycall_12, &
hiscall_12,hisgrid_6,sync,nsnr,dtx,nfreq,decoded,nft)
use packjt
use timer_module, only: timer
parameter (NMAX=60*12000,LN=1152*63)
character decoded*22
character*12 mycall_12,hiscall_12
character*6 mycall,hiscall,hisgrid_6
character*4 hisgrid
logical ltext
complex c00(0:720000) !Complex spectrum of dd()
complex c0(0:720000) !Complex data for dd()
! integer*8 count0,count1,clkfreq
real a(3)
real dd(NMAX) !Raw data sampled at 12000 Hz
real s3(LN) !Symbol spectra
real s3a(LN) !Symbol spectra
integer dat4(12) !Decoded message (as 12 integers)
integer dat4x(12)
data nc1z/-1/,nc2z/-1/,ng2z/-1/
save
call timer('qra64a ',0)
decoded=' '
if(nfqso.lt.nf1 .or. nfqso.gt.nf2) go to 900
nft=99
nsnr=-30
mycall=mycall_12(1:6) !### May need fixing ###
hiscall=hiscall_12(1:6)
hisgrid=hisgrid_6(1:4)
call packcall(mycall,nc1,ltext)
call packcall(hiscall,nc2,ltext)
call packgrid(hisgrid,ng2,ltext)
nSubmode=0
if(mode64.eq.2) nSubmode=1
if(mode64.eq.4) nSubmode=2
if(mode64.eq.8) nSubmode=3
if(mode64.eq.16) nSubmode=4
b90=1.0
nFadingModel=1
if(nc1.ne.nc1z .or. nc2.ne.nc2z .or. ng2.ne.ng2z) then
do naptype=0,5
call qra64_dec(s3,nc1,nc2,ng2,naptype,1,nSubmode,b90, &
nFadingModel,dat4,snr2,irc)
enddo
nc1z=nc1
nc2z=nc2
ng2z=ng2
endif
maxf1=0
! write(60) npts,dd(1:npts),nf1,nf2,nfqso,ntol,mode64,maxf1
call timer('sync64 ',0)
call sync64(dd,npts,nf1,nf2,nfqso,ntol,mode64,maxf1,dtx,f0,jpk,kpk,sync,c00)
call timer('sync64 ',1)
irc=-99
if(sync.lt.float(minsync)) go to 900
npts2=npts/2
itz=10
if(mode64.eq.4) itz=9
if(mode64.eq.2) itz=7
if(mode64.eq.1) itz=5
naptype=4
LL=64*(mode64+2)
NN=63
! do itry0=1,3
do itry0=1,1
idf0=itry0/2
if(mod(itry0,2).eq.0) idf0=-idf0
a(1)=-(f0+0.248*(idf0-0.33*kpk))
nfreq=nint(-a(1))
a(3)=0.
! do itry1=1,3
do itry1=1,1
idf1=itry1/2
if(mod(itry1,2).eq.0) idf1=-idf1
a(2)=-0.67*(idf1 + 0.67*kpk)
call twkfreq(c00,c0,npts2,6000.0,a)
call spec64(c0,npts2,mode64,jpk,s3a,LL,NN)
ircmin=99
do iter=itz,0,-1
b90=1.728**iter
s3(1:LL*NN)=s3a(1:LL*NN)
call timer('qra64_de',0)
call qra64_dec(s3,nc1,nc2,ng2,naptype,0,nSubmode,b90, &
nFadingModel,dat4,snr2,irc)
call timer('qra64_de',1)
if(abs(snr2).gt.30.) snr2=-30.0
if(irc.eq.0) go to 10
if(irc.gt.0 .and. irc.le.ircmin) then
dat4x=dat4
b90x=b90
snr2x=snr2
ircmin=irc
endif
enddo
if(ircmin.ne.99) then
dat4=dat4x
b90=b90x
snr2=snr2x
irc=ircmin
endif
10 decoded=' '
! write(73,3001) iter,b90,snr2,irc
if(irc.ge.0) then
call unpackmsg(dat4,decoded) !Unpack the user message
call fmtmsg(decoded,iz)
nft=100 + irc
nsnr=nint(snr2)
else
snr2=0.
endif
enddo
enddo
900 continue
if(index(decoded,"000AAA ").ge.1) then
! Suppress a certain type of garbage decode.
decoded=' '
irc=-1
endif
if(irc.lt.0) then
sy=max(1.0,sync+1.0)
if(nSubmode.eq.0) nsnr=nint(10.0*log10(sy)-38.0) !A
if(nSubmode.eq.1) nsnr=nint(10.0*log10(sy)-36.0) !B
if(nSubmode.eq.2) nsnr=nint(10.0*log10(sy)-34.0) !C
if(nSubmode.eq.3) nsnr=nint(10.0*log10(sy)-29.0) !D
if(nSubmode.eq.4) nsnr=nint(10.0*log10(sy)-24.0) !E
endif
! write(70,3303) sync,snr2,nsnr,irc
!3303 format(2f8.1,2i5)
call timer('qra64a ',1)
return
end subroutine qra64a