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|
module ft4_decode
type :: ft4_decoder
procedure(ft4_decode_callback), pointer :: callback
contains
procedure :: decode
end type ft4_decoder
abstract interface
subroutine ft4_decode_callback (this,sync,snr,dt,freq,decoded,nap,qual)
import ft4_decoder
implicit none
class(ft4_decoder), intent(inout) :: this
real, intent(in) :: sync
integer, intent(in) :: snr
real, intent(in) :: dt
real, intent(in) :: freq
character(len=37), intent(in) :: decoded
integer, intent(in) :: nap
real, intent(in) :: qual
end subroutine ft4_decode_callback
end interface
contains
subroutine decode(this,callback,iwave,nQSOProgress,nfqso, &
nfa,nfb,ndepth,lapcqonly,ncontest,mycall,hiscall)
use timer_module, only: timer
use packjt77
include 'ft4/ft4_params.f90'
parameter (MAXCAND=100)
class(ft4_decoder), intent(inout) :: this
procedure(ft4_decode_callback) :: callback
parameter (NSS=NSPS/NDOWN,NDMAX=NMAX/NDOWN)
character message*37,msgsent*37
character c77*77
character*37 decodes(100)
character*17 cdatetime0
character*12 mycall,hiscall
character*12 mycall0,hiscall0
character*6 hhmmss
complex cd2(0:NDMAX-1) !Complex waveform
complex cb(0:NDMAX-1)
complex cd(0:NN*NSS-1) !Complex waveform
complex ctwk(2*NSS),ctwk2(2*NSS,-16:16)
real a(5)
real bitmetrics(2*NN,3)
real dd(NMAX)
real llr(2*ND),llra(2*ND),llrb(2*ND),llrc(2*ND),llrd(2*ND)
real candidate(2,MAXCAND)
real savg(NH1),sbase(NH1)
integer apbits(2*ND)
integer apmy_ru(28),aphis_fd(28)
integer*2 iwave(NMAX) !Raw received data
integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND)
integer*1 message91(91)
integer*1 hbits(2*NN)
integer i4tone(103)
integer nappasses(0:5) ! # of decoding passes for QSO States 0-5
integer naptypes(0:5,4) ! nQSOProgress, decoding pass
integer mcq(29),mcqru(29),mcqfd(29),mcqtest(29),mcqww(29)
integer mrrr(19),m73(19),mrr73(19)
logical nohiscall,unpk77_success
logical first, dobigfft
logical dosubtract,doosd
logical badsync
logical, intent(in) :: lapcqonly
data first/.true./
data mcq/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0/
data mcqru/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,1,0,0,1,1,0,0/
data mcqfd/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,1,0,0,0,1,0/
data mcqtest/0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,0,1,0,1,1,1,1,1,1,0,0,1,0/
data mcqww/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,1,0,1,1,1,1,0/
data mrrr/0,1,1,1,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1/
data m73/0,1,1,1,1,1,1,0,1,0,0,1,0,1,0,0,0,0,1/
data mrr73/0,1,1,1,1,1,1,0,0,1,1,1,0,1,0,1,0,0,1/
data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
save fs,dt,tt,txt,twopi,h,first,apbits,nappasses,naptypes, &
mycall0,hiscall0,ctwk2
this%callback => callback
hhmmss=cdatetime0(8:13)
dxcall13=hiscall ! initialize for use in packjt77
mycall13=mycall
smax1=0.
nd1=0
if(first) then
fs=12000.0/NDOWN !Sample rate after downsampling
dt=1/fs !Sample interval after downsample (s)
tt=NSPS*dt !Duration of "itone" symbols (s)
txt=NZ*dt !Transmission length (s) without ramp up/down
twopi=8.0*atan(1.0)
h=1.0
do idf=-16,16
a=0.
a(1)=real(idf)
ctwk=1.
call twkfreq1(ctwk,2*NSS,fs/2.0,a,ctwk2(:,idf))
enddo
mcq=2*mod(mcq+rvec(1:29),2)-1
mcqru=2*mod(mcqru+rvec(1:29),2)-1
mcqfd=2*mod(mcqfd+rvec(1:29),2)-1
mcqtest=2*mod(mcqtest+rvec(1:29),2)-1
mcqww=2*mod(mcqww+rvec(1:29),2)-1
mrrr=2*mod(mrrr+rvec(59:77),2)-1
m73=2*mod(m73+rvec(59:77),2)-1
mrr73=2*mod(mrr73+rvec(59:77),2)-1
nappasses(0)=2
nappasses(1)=2
nappasses(2)=2
nappasses(3)=2
nappasses(4)=2
nappasses(5)=3
! iaptype
!------------------------
! 1 CQ ??? ??? (29 ap bits)
! 2 MyCall ??? ??? (29 ap bits)
! 3 MyCall DxCall ??? (58 ap bits)
! 4 MyCall DxCall RRR (77 ap bits)
! 5 MyCall DxCall 73 (77 ap bits)
! 6 MyCall DxCall RR73 (77 ap bits)
!********
naptypes(0,1:4)=(/1,2,0,0/) ! Tx6 selected (CQ)
naptypes(1,1:4)=(/2,3,0,0/) ! Tx1
naptypes(2,1:4)=(/2,3,0,0/) ! Tx2
naptypes(3,1:4)=(/3,6,0,0/) ! Tx3
naptypes(4,1:4)=(/3,6,0,0/) ! Tx4
naptypes(5,1:4)=(/3,1,2,0/) ! Tx5
mycall0=''
hiscall0=''
first=.false.
endif
l1=index(mycall,char(0))
if(l1.ne.0) mycall(l1:)=" "
l1=index(hiscall,char(0))
if(l1.ne.0) hiscall(l1:)=" "
if(mycall.ne.mycall0 .or. hiscall.ne.hiscall0) then
apbits=0
apbits(1)=99
apbits(30)=99
apmy_ru=0
aphis_fd=0
if(len(trim(mycall)) .lt. 3) go to 10
nohiscall=.false.
hiscall0=hiscall
if(len(trim(hiscall0)).lt.3) then
hiscall0=mycall ! use mycall for dummy hiscall - mycall won't be hashed.
nohiscall=.true.
endif
message=trim(mycall)//' '//trim(hiscall0)//' RR73'
i3=-1
n3=-1
call pack77(message,i3,n3,c77)
call unpack77(c77,1,msgsent,unpk77_success)
if(i3.ne.1 .or. (message.ne.msgsent) .or. .not.unpk77_success) go to 10
read(c77,'(77i1)') message77
apmy_ru=2*mod(message77(1:28)+rvec(2:29),2)-1
aphis_fd=2*mod(message77(30:57)+rvec(29:56),2)-1
message77=mod(message77+rvec,2)
call encode174_91(message77,cw)
apbits=2*cw-1
if(nohiscall) apbits(30)=99
10 continue
mycall0=mycall
hiscall0=hiscall
endif
ndecodes=0
decodes=' '
fa=nfa
fb=nfb
dd=iwave
! ndepth=3: 3 passes, bp+osd
! ndepth=2: 3 passes, bp only
! ndepth=1: 1 pass, no subtraction
max_iterations=40
syncmin=1.2
dosubtract=.true.
doosd=.true.
nsp=3
if(ndepth.eq.2) then
doosd=.false.
endif
if(ndepth.eq.1) then
nsp=1
dosubtract=.false.
doosd=.false.
endif
do isp = 1,nsp
if(isp.eq.2) then
if(ndecodes.eq.0) exit
nd1=ndecodes
elseif(isp.eq.3) then
nd2=ndecodes-nd1
if(nd2.eq.0) exit
endif
candidate=0.0
ncand=0
call timer('getcand4',0)
call getcandidates4(dd,fa,fb,syncmin,nfqso,MAXCAND,savg,candidate, &
ncand,sbase)
call timer('getcand4',1)
dobigfft=.true.
do icand=1,ncand
f0=candidate(1,icand)
snr=candidate(2,icand)-1.0
call timer('ft4_down',0)
call ft4_downsample(dd,dobigfft,f0,cd2) !Downsample to 32 Sam/Sym
call timer('ft4_down',1)
if(dobigfft) dobigfft=.false.
sum2=sum(cd2*conjg(cd2))/(real(NMAX)/real(NDOWN))
if(sum2.gt.0.0) cd2=cd2/sqrt(sum2)
! Sample rate is now 12000/18 = 666.67 samples/second
do iseg=1,3 ! DT search is done over 3 segments
do isync=1,2
if(isync.eq.1) then
idfmin=-12
idfmax=12
idfstp=3
ibmin=-344
ibmax=1012
if(iseg.eq.1) then
ibmin=108
ibmax=560
elseif(iseg.eq.2) then
smax1=smax
ibmin=560
ibmax=1012
elseif(iseg.eq.3) then
ibmin=-344
ibmax=108
endif
ibstp=4
else
idfmin=idfbest-4
idfmax=idfbest+4
idfstp=1
ibmin=ibest-5
ibmax=ibest+5
ibstp=1
endif
ibest=-1
idfbest=0
smax=-99.
call timer('sync4d ',0)
do idf=idfmin,idfmax,idfstp
do istart=ibmin,ibmax,ibstp
call sync4d(cd2,istart,ctwk2(:,idf),1,sync) !Find sync power
if(sync.gt.smax) then
smax=sync
ibest=istart
idfbest=idf
endif
enddo
enddo
call timer('sync4d ',1)
enddo
if(iseg.eq.1) smax1=smax
if(smax.lt.1.2) cycle
if(iseg.gt.1 .and. smax.lt.smax1) cycle
f1=f0+real(idfbest)
if( f1.le.10.0 .or. f1.ge.4990.0 ) cycle
call timer('ft4down ',0)
call ft4_downsample(dd,dobigfft,f1,cb) !Final downsample, corrected f0
call timer('ft4down ',1)
sum2=sum(abs(cb)**2)/(real(NSS)*NN)
if(sum2.gt.0.0) cb=cb/sqrt(sum2)
cd=0.
if(ibest.ge.0) then
it=min(NDMAX-1,ibest+NN*NSS-1)
np=it-ibest+1
cd(0:np-1)=cb(ibest:it)
else
cd(-ibest:ibest+NN*NSS-1)=cb(0:NN*NSS+2*ibest-1)
endif
call timer('bitmet ',0)
call get_ft4_bitmetrics(cd,bitmetrics,badsync)
call timer('bitmet ',1)
if(badsync) cycle
hbits=0
where(bitmetrics(:,1).ge.0) hbits=1
ns1=count(hbits( 1: 8).eq.(/0,0,0,1,1,0,1,1/))
ns2=count(hbits( 67: 74).eq.(/0,1,0,0,1,1,1,0/))
ns3=count(hbits(133:140).eq.(/1,1,1,0,0,1,0,0/))
ns4=count(hbits(199:206).eq.(/1,0,1,1,0,0,0,1/))
nsync_qual=ns1+ns2+ns3+ns4
if(nsync_qual.lt. 20) cycle
scalefac=2.83
llra( 1: 58)=bitmetrics( 9: 66, 1)
llra( 59:116)=bitmetrics( 75:132, 1)
llra(117:174)=bitmetrics(141:198, 1)
llra=scalefac*llra
llrb( 1: 58)=bitmetrics( 9: 66, 2)
llrb( 59:116)=bitmetrics( 75:132, 2)
llrb(117:174)=bitmetrics(141:198, 2)
llrb=scalefac*llrb
llrc( 1: 58)=bitmetrics( 9: 66, 3)
llrc( 59:116)=bitmetrics( 75:132, 3)
llrc(117:174)=bitmetrics(141:198, 3)
llrc=scalefac*llrc
apmag=maxval(abs(llra))*1.1
npasses=3+nappasses(nQSOProgress)
if(lapcqonly) npasses=4
if(ndepth.eq.1) npasses=3
if(ncontest.ge.6) npasses=3 ! Don't support Fox and Hound
do ipass=1,npasses
if(ipass.eq.1) llr=llra
if(ipass.eq.2) llr=llrb
if(ipass.eq.3) llr=llrc
if(ipass.le.3) then
apmask=0
iaptype=0
endif
if(ipass .gt. 3) then
llrd=llrc
iaptype=naptypes(nQSOProgress,ipass-3)
if(lapcqonly) iaptype=1
! ncontest=0 : NONE
! 1 : NA_VHF
! 2 : EU_VHF
! 3 : FIELD DAY
! 4 : RTTY
! 5 : WW_DIGI
! 6 : FOX
! 7 : HOUND
!
! Conditions that cause us to bail out of AP decoding
napwid=80
if(ncontest.le.5 .and. iaptype.ge.3 .and. (abs(f1-nfqso).gt.napwid) ) cycle
if(iaptype.ge.2 .and. apbits(1).gt.1) cycle ! No, or nonstandard, mycall
if(iaptype.ge.3 .and. apbits(30).gt.1) cycle ! No, or nonstandard, dxcall
if(iaptype.eq.1) then ! CQ or CQ TEST or CQ FD or CQ RU or CQ WW
apmask=0
apmask(1:29)=1
if( ncontest.eq.0 ) llrd(1:29)=apmag*mcq(1:29)
if( ncontest.eq.1 ) llrd(1:29)=apmag*mcqtest(1:29)
if( ncontest.eq.2 ) llrd(1:29)=apmag*mcqtest(1:29)
if( ncontest.eq.3 ) llrd(1:29)=apmag*mcqfd(1:29)
if( ncontest.eq.4 ) llrd(1:29)=apmag*mcqru(1:29)
if( ncontest.eq.5 ) llrd(1:29)=apmag*mcqww(1:29)
endif
if(iaptype.eq.2) then ! MyCall,???,???
apmask=0
if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.5) then
apmask(1:29)=1
llrd(1:29)=apmag*apbits(1:29)
else if(ncontest.eq.2) then
apmask(1:28)=1
llrd(1:28)=apmag*apbits(1:28)
else if(ncontest.eq.3) then
apmask(1:28)=1
llrd(1:28)=apmag*apbits(1:28)
else if(ncontest.eq.4) then
apmask(2:29)=1
llrd(2:29)=apmag*apmy_ru(1:28)
endif
endif
if(iaptype.eq.3) then ! MyCall,DxCall,???
apmask=0
if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.2.or.ncontest.eq.5) then
apmask(1:58)=1
llrd(1:58)=apmag*apbits(1:58)
else if(ncontest.eq.3) then ! Field Day
apmask(1:56)=1
llrd(1:28)=apmag*apbits(1:28)
llrd(29:56)=apmag*aphis_fd(1:28)
else if(ncontest.eq.4) then
apmask(2:57)=1
llrd(2:29)=apmag*apmy_ru(1:28)
llrd(30:57)=apmag*apbits(30:57)
endif
endif
if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then
apmask=0
if(ncontest.le.5) then
apmask(1:77)=1 ! mycall, hiscall, RRR|73|RR73
if(iaptype.eq.6) llrd(1:77)=apmag*apbits(1:77)
endif
endif
llr=llrd
endif
message77=0
dmin=0.0
ndeep=2
maxosd=2
if(abs(nfqso-f1).le.napwid) then
ndeep=2
maxosd=3
endif
if(.not.doosd) maxosd = -1
call timer('dec174_91 ',0)
Keff=91
call decode174_91(llr,Keff,maxosd,ndeep,apmask,message91,cw, &
ntype,nharderror,dmin)
message77=message91(1:77)
call timer('dec174_91 ',1)
if(sum(message77).eq.0) cycle
if( nharderror.ge.0 ) then
message77=mod(message77+rvec,2) ! remove rvec scrambling
write(c77,'(77i1)') message77(1:77)
call unpack77(c77,1,message,unpk77_success)
if(.not.unpk77_success) exit
if(dosubtract) then
call get_ft4_tones_from_77bits(message77,i4tone)
dt=real(ibest)/666.67
call timer('subtract',0)
call subtractft4(dd,i4tone,f1,dt)
call timer('subtract',1)
endif
idupe=0
do i=1,ndecodes
if(decodes(i).eq.message) idupe=1
enddo
if(idupe.eq.1) exit
ndecodes=ndecodes+1
decodes(ndecodes)=message
if(snr.gt.0.0) then
xsnr=10*log10(snr)-14.8
else
xsnr=-21.0
endif
nsnr=nint(max(-21.0,xsnr))
xdt=ibest/666.67 - 0.5
qual=1.0-(nharderror+dmin)/60.0
call this%callback(smax,nsnr,xdt,f1,message,iaptype,qual)
exit
endif
enddo !Sequence estimation
if(nharderror.ge.0) exit
enddo !3 DT segments
enddo !Candidate list
enddo !Subtraction loop
return
end subroutine decode
end module ft4_decode
|
