mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-10-31 23:57:10 -04:00
9a5f73e00d
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7445 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
200 lines
5.2 KiB
Fortran
200 lines
5.2 KiB
Fortran
subroutine msk40spd(cbig,n,ntol,mycall,hiscall,bswl,nhasharray,recent_calls, &
|
|
nrecent,nsuccess,msgreceived,fc,fret,tret,navg)
|
|
! msk40 short-ping-decoder
|
|
|
|
use timer_module, only: timer
|
|
|
|
parameter (NSPM=240, MAXSTEPS=150, NFFT=NSPM, MAXCAND=5, NPATTERNS=6)
|
|
character*6 mycall,hiscall
|
|
character*22 msgreceived
|
|
character*12 recent_calls(nrecent)
|
|
complex cbig(n)
|
|
complex cdat(3*NSPM) !Analytic signal
|
|
complex c(NSPM)
|
|
complex ct(NSPM)
|
|
complex ctmp(NFFT)
|
|
integer, dimension(1) :: iloc
|
|
integer indices(MAXSTEPS)
|
|
integer npkloc(10)
|
|
integer navpatterns(3,NPATTERNS)
|
|
integer navmask(3)
|
|
integer nstart(MAXCAND)
|
|
integer nhasharray(nrecent,nrecent)
|
|
logical ismask(NFFT)
|
|
logical*1 bswl
|
|
real detmet(-2:MAXSTEPS+3)
|
|
real detmet2(-2:MAXSTEPS+3)
|
|
real detfer(MAXSTEPS)
|
|
real rcw(12)
|
|
real ferrs(MAXCAND)
|
|
real snrs(MAXCAND)
|
|
real tonespec(NFFT)
|
|
real tpat(NPATTERNS)
|
|
real*8 dt, df, fs, pi, twopi
|
|
logical first
|
|
data first/.true./
|
|
data navpatterns/ &
|
|
0,1,0, &
|
|
1,0,0, &
|
|
0,0,1, &
|
|
1,1,0, &
|
|
0,1,1, &
|
|
1,1,1/
|
|
data tpat/1.5,0.5,2.5,1.0,2.0,1.5/
|
|
save df,first,fs,pi,twopi,dt,tframe,rcw
|
|
|
|
if(first) then
|
|
nmatchedfilter=1
|
|
! define half-sine pulse and raised-cosine edge window
|
|
pi=4d0*datan(1d0)
|
|
twopi=8d0*datan(1d0)
|
|
fs=12000.0
|
|
dt=1.0/fs
|
|
df=fs/NFFT
|
|
tframe=NSPM/fs
|
|
|
|
do i=1,12
|
|
angle=(i-1)*pi/12.0
|
|
rcw(i)=(1-cos(angle))/2
|
|
enddo
|
|
|
|
first=.false.
|
|
endif
|
|
|
|
|
|
! fill the detmet, detferr arrays
|
|
nstep=(n-NSPM)/60 ! 20ms/4=5ms steps
|
|
detmet=0
|
|
detmet2=0
|
|
detfer=-999.99
|
|
nfhi=2*(fc+500)
|
|
nflo=2*(fc-500)
|
|
ihlo=(nfhi-2*ntol)/df+1
|
|
ihhi=(nfhi+2*ntol)/df+1
|
|
illo=(nflo-2*ntol)/df+1
|
|
ilhi=(nflo+2*ntol)/df+1
|
|
i2000=nflo/df+1
|
|
i4000=nfhi/df+1
|
|
do istp=1,nstep
|
|
ns=1+60*(istp-1)
|
|
ne=ns+NSPM-1
|
|
if( ne .gt. n ) exit
|
|
ctmp=cmplx(0.0,0.0)
|
|
ctmp(1:NSPM)=cbig(ns:ne)
|
|
|
|
! Coarse carrier frequency sync - seek tones at 2000 Hz and 4000 Hz in
|
|
! squared signal spectrum.
|
|
|
|
ctmp=ctmp**2
|
|
ctmp(1:12)=ctmp(1:12)*rcw
|
|
ctmp(NSPM-11:NSPM)=ctmp(NSPM-11:NSPM)*rcw(12:1:-1)
|
|
call four2a(ctmp,NFFT,1,-1,1)
|
|
tonespec=abs(ctmp)**2
|
|
|
|
ismask=.false.
|
|
ismask(ihlo:ihhi)=.true. ! high tone search window
|
|
iloc=maxloc(tonespec,ismask)
|
|
ihpk=iloc(1)
|
|
deltah=-real( (ctmp(ihpk-1)-ctmp(ihpk+1)) / (2*ctmp(ihpk)-ctmp(ihpk-1)-ctmp(ihpk+1)) )
|
|
ah=tonespec(ihpk)
|
|
ahavp=(sum(tonespec,ismask)-ah)/count(ismask)
|
|
trath=ah/(ahavp+0.01)
|
|
ismask=.false.
|
|
ismask(illo:ilhi)=.true. ! window for low tone
|
|
iloc=maxloc(tonespec,ismask)
|
|
ilpk=iloc(1)
|
|
deltal=-real( (ctmp(ilpk-1)-ctmp(ilpk+1)) / (2*ctmp(ilpk)-ctmp(ilpk-1)-ctmp(ilpk+1)) )
|
|
al=tonespec(ilpk)
|
|
alavp=(sum(tonespec,ismask)-al)/count(ismask)
|
|
tratl=al/(alavp+0.01)
|
|
fdiff=(ihpk+deltah-ilpk-deltal)*df
|
|
ferrh=(ihpk+deltah-i4000)*df/2.0
|
|
ferrl=(ilpk+deltal-i2000)*df/2.0
|
|
if( ah .ge. al ) then
|
|
ferr=ferrh
|
|
else
|
|
ferr=ferrl
|
|
endif
|
|
detmet(istp)=max(ah,al)
|
|
detmet2(istp)=max(trath,tratl)
|
|
detfer(istp)=ferr
|
|
enddo ! end of detection-metric and frequency error estimation loop
|
|
|
|
call indexx(detmet(1:nstep),nstep,indices) !find median of detection metric vector
|
|
xmed=detmet(indices(nstep/4))
|
|
detmet=detmet/xmed ! noise floor of detection metric is 1.0
|
|
ndet=0
|
|
|
|
do ip=1,MAXCAND ! Find candidates
|
|
iloc=maxloc(detmet(1:nstep))
|
|
il=iloc(1)
|
|
if( (detmet(il) .lt. 3.5) ) exit
|
|
if( abs(detfer(il)) .le. ntol ) then
|
|
ndet=ndet+1
|
|
nstart(ndet)=1+(il-1)*60+1
|
|
ferrs(ndet)=detfer(il)
|
|
snrs(ndet)=12.0*log10(detmet(il))/2-9.0
|
|
endif
|
|
detmet(il)=0.0
|
|
enddo
|
|
|
|
if( ndet .lt. 3 ) then
|
|
do ip=1,MAXCAND-ndet ! Find candidates
|
|
iloc=maxloc(detmet2(1:nstep))
|
|
il=iloc(1)
|
|
if( (detmet2(il) .lt. 12.0) ) exit
|
|
if( abs(detfer(il)) .le. ntol ) then
|
|
ndet=ndet+1
|
|
nstart(ndet)=1+(il-1)*60+1
|
|
ferrs(ndet)=detfer(il)
|
|
snrs(ndet)=12.0*log10(detmet2(il))/2-9.0
|
|
endif
|
|
detmet2(il)=0.0
|
|
enddo
|
|
endif
|
|
|
|
nsuccess=0
|
|
msgreceived=' '
|
|
npeaks=2
|
|
ntol0=29
|
|
deltaf=7.2
|
|
do icand=1,ndet ! Try to sync/demod/decode each candidate.
|
|
ib=max(1,nstart(icand)-NSPM)
|
|
ie=ib-1+3*NSPM
|
|
if( ie .gt. n ) then
|
|
ie=n
|
|
ib=ie-3*NSPM+1
|
|
endif
|
|
cdat=cbig(ib:ie)
|
|
fo=fc+ferrs(icand)
|
|
xsnr=snrs(icand)
|
|
do iav=1,NPATTERNS
|
|
navmask=navpatterns(1:3,iav)
|
|
call msk40sync(cdat,3,ntol0,deltaf,navmask,npeaks,fo,fest,npkloc, &
|
|
nsyncsuccess,c)
|
|
if( nsyncsuccess .eq. 0 ) cycle
|
|
|
|
do ipk=1,npeaks
|
|
do is=1,3
|
|
ic0=npkloc(ipk)
|
|
if( is.eq.2) ic0=max(1,ic0-1)
|
|
if( is.eq.3) ic0=min(NSPM,ic0+1)
|
|
ct=cshift(c,ic0-1)
|
|
call msk40decodeframe(ct,mycall,hiscall,xsnr,bswl,nhasharray, &
|
|
recent_calls,nrecent,msgreceived,ndecodesuccess)
|
|
if( ndecodesuccess .gt. 0 ) then
|
|
!write(*,*) icand, iav, ipk, is, tret, fret, msgreceived
|
|
tret=(nstart(icand)+NSPM/2)/fs
|
|
fret=fest
|
|
navg=sum(navmask)
|
|
nsuccess=ndecodesuccess
|
|
return
|
|
endif
|
|
enddo
|
|
enddo
|
|
enddo
|
|
enddo ! candidate loop
|
|
|
|
return
|
|
end subroutine msk40spd
|