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https://github.com/saitohirga/WSJT-X.git
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526 lines
18 KiB
Fortran
526 lines
18 KiB
Fortran
module ft4_decode
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type :: ft4_decoder
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procedure(ft4_decode_callback), pointer :: callback
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contains
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procedure :: decode
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end type ft4_decoder
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abstract interface
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subroutine ft4_decode_callback (this,sync,snr,dt,freq,decoded,nap,qual)
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import ft4_decoder
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implicit none
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class(ft4_decoder), intent(inout) :: this
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real, intent(in) :: sync
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integer, intent(in) :: snr
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real, intent(in) :: dt
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real, intent(in) :: freq
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character(len=37), intent(in) :: decoded
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integer, intent(in) :: nap
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real, intent(in) :: qual
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end subroutine ft4_decode_callback
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end interface
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contains
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subroutine decode(this,callback,iwave,nQSOProgress,nfqso, &
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nutc,nfa,nfb,ndepth,ncontest,mycall,hiscall)
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use timer_module, only: timer
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use packjt77
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include 'ft4/ft4_params.f90'
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class(ft4_decoder), intent(inout) :: this
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procedure(ft4_decode_callback) :: callback
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parameter (NSS=NSPS/NDOWN,NDMAX=NMAX/NDOWN)
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character message*37,msgsent*37
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character c77*77
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character*37 decodes(100)
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character*512 data_dir,fname
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character*17 cdatetime0
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character*12 mycall,hiscall
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character*12 mycall0,hiscall0
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character*6 hhmmss
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character*4 cqstr,cqstr0
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complex cd2(0:NDMAX-1) !Complex waveform
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complex cb(0:NDMAX-1)
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complex cd(0:NN*NSS-1) !Complex waveform
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complex ctwk(2*NSS),ctwk2(2*NSS,-16:16)
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complex csymb(NSS)
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complex cs(0:3,NN)
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real s4(0:3,NN)
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real bmeta(2*NN),bmetb(2*NN),bmetc(2*NN)
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real a(5)
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real dd(NMAX)
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real llr(2*ND),llra(2*ND),llrb(2*ND),llrc(2*ND),llrd(2*ND)
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real s2(0:255)
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real candidate(3,100)
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real savg(NH1),sbase(NH1)
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integer apbits(2*ND)
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integer apmy_ru(28),aphis_fd(28)
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integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(0:3)
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integer*2 iwave(NMAX) !Raw received data
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integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND)
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integer*1 hbits(2*NN)
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integer graymap(0:3)
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integer i4tone(103)
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integer ip(1)
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integer nappasses(0:5) ! # of decoding passes for QSO States 0-5
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integer naptypes(0:5,4) ! nQSOProgress, decoding pass
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integer mcq(29)
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integer mrrr(19),m73(19),mrr73(19)
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logical nohiscall,unpk77_success
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logical one(0:255,0:7) ! 256 4-symbol sequences, 8 bits
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logical first, dobigfft
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logical dosubtract
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data icos4a/0,1,3,2/
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data icos4b/1,0,2,3/
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data icos4c/2,3,1,0/
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data icos4d/3,2,0,1/
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data graymap/0,1,3,2/
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data first/.true./
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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/
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data mrrr/0,1,1,1,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1/
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data m73/0,1,1,1,1,1,1,0,1,0,0,1,0,1,0,0,0,0,1/
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data mrr73/0,1,1,1,1,1,1,0,0,1,1,1,0,1,0,1,0,0,1/
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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, &
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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, &
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0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
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save fs,dt,tt,txt,twopi,h,one,first,apbits,nappasses,naptypes, &
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mycall0,hiscall0,cqstr0,ctwk2
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this%callback => callback
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hhmmss=cdatetime0(8:13)
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dxcall13=hiscall
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mycall13=mycall
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if(first) then
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fs=12000.0/NDOWN !Sample rate after downsampling
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dt=1/fs !Sample interval after downsample (s)
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tt=NSPS*dt !Duration of "itone" symbols (s)
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txt=NZ*dt !Transmission length (s) without ramp up/down
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twopi=8.0*atan(1.0)
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h=1.0
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one=.false.
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do i=0,255
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do j=0,7
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if(iand(i,2**j).ne.0) one(i,j)=.true.
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enddo
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enddo
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do idf=-16,16
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a=0.
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a(1)=real(idf)
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ctwk=1.
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call twkfreq1(ctwk,2*NSS,fs/2.0,a,ctwk2(:,idf))
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enddo
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mrrr=2*mod(mrrr+rvec(59:77),2)-1
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m73=2*mod(m73+rvec(59:77),2)-1
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mrr73=2*mod(mrr73+rvec(59:77),2)-1
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nappasses(0)=2
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nappasses(1)=2
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nappasses(2)=2
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nappasses(3)=2
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nappasses(4)=2
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nappasses(5)=3
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! iaptype
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!------------------------
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! 1 CQ ??? ??? (29 ap bits)
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! 2 MyCall ??? ??? (29 ap bits)
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! 3 MyCall DxCall ??? (58 ap bits)
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! 4 MyCall DxCall RRR (77 ap bits)
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! 5 MyCall DxCall 73 (77 ap bits)
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! 6 MyCall DxCall RR73 (77 ap bits)
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!********
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naptypes(0,1:4)=(/1,2,0,0/) ! Tx6 selected (CQ)
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naptypes(1,1:4)=(/2,3,0,0/) ! Tx1
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naptypes(2,1:4)=(/2,3,0,0/) ! Tx2
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naptypes(3,1:4)=(/3,6,0,0/) ! Tx3
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naptypes(4,1:4)=(/3,6,0,0/) ! Tx4
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naptypes(5,1:4)=(/3,1,2,0/) ! Tx5
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mycall0=''
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hiscall0=''
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cqstr0=''
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first=.false.
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endif
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if(cqstr.ne.cqstr0) then
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i0=index(cqstr,' ')
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if(i0.le.1) then
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message='CQ A1AA AA01'
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else
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message='CQ '//cqstr(1:i0-1)//' A1AA AA01'
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endif
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i3=-1
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n3=-1
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call pack77(message,i3,n3,c77)
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call unpack77(c77,1,msgsent,unpk77_success)
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read(c77,'(29i1)') mcq
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mcq=2*mod(mcq+rvec(1:29),2)-1
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cqstr0=cqstr
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endif
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l1=index(mycall,char(0))
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if(l1.ne.0) mycall(l1:)=" "
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l1=index(hiscall,char(0))
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if(l1.ne.0) hiscall(l1:)=" "
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if(mycall.ne.mycall0 .or. hiscall.ne.hiscall0) then
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apbits=0
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apbits(1)=99
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apbits(30)=99
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apmy_ru=0
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aphis_fd=0
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if(len(trim(mycall)) .lt. 3) go to 10
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nohiscall=.false.
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hiscall0=hiscall
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if(len(trim(hiscall0)).lt.3) then
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hiscall0=mycall ! use mycall for dummy hiscall - mycall won't be hashed.
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nohiscall=.true.
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endif
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message=trim(mycall)//' '//trim(hiscall0)//' RR73'
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i3=-1
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n3=-1
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call pack77(message,i3,n3,c77)
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call unpack77(c77,1,msgsent,unpk77_success)
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if(i3.ne.1 .or. (message.ne.msgsent) .or. .not.unpk77_success) go to 10
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read(c77,'(77i1)') message77
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apmy_ru=2*mod(message77(1:28)+rvec(2:29),2)-1
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aphis_fd=2*mod(message77(30:57)+rvec(29:56),2)-1
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message77=mod(message77+rvec,2)
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call encode174_91(message77,cw)
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apbits=2*cw-1
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if(nohiscall) apbits(30)=99
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10 continue
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mycall0=mycall
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hiscall0=hiscall
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endif
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maxcand=100
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ndecodes=0
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decodes=' '
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fa=nfa
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fb=nfb
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dd=iwave
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! ndepth=3: 2 passes, subtract on each pass
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! ndepth=2: 1 pass, no subtraction
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! ndepth=1: 1 pass, no subtraction, fewer candidates
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max_iterations=40
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syncmin=1.2
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dosubtract=.true.
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nsp=3
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if(ndepth.lt.3) then
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nsp=1
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dosubtract=.false.
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endif
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if(ndepth.eq.1) syncmin=2.0
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do isp = 1,nsp
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if(isp.eq.2) then
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if(ndecodes.eq.0) exit
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nd1=ndecodes
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elseif(isp.eq.3) then
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nd2=ndecodes-nd1
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if(nd2.eq.0) exit
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endif
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candidate=0.0
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ncand=0
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call timer('getcand4',0)
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call getcandidates4(dd,fa,fb,syncmin,nfqso,maxcand,savg,candidate, &
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ncand,sbase)
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call timer('getcand4',1)
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dobigfft=.true.
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do icand=1,ncand
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f0=candidate(1,icand)
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snr=candidate(3,icand)-1.0
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call timer('ft4_down',0)
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call ft4_downsample(dd,dobigfft,f0,cd2) !Downsample to 32 Sam/Sym
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call timer('ft4_down',1)
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if(dobigfft) dobigfft=.false.
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sum2=sum(cd2*conjg(cd2))/(real(NMAX)/real(NDOWN))
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if(sum2.gt.0.0) cd2=cd2/sqrt(sum2)
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! Sample rate is now 12000/18 = 666.67 samples/second
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do isync=1,2
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if(isync.eq.1) then
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idfmin=-12
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idfmax=12
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idfstp=3
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ibmin=-344
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ibmax=1012
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ibstp=4
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else
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idfmin=idfbest-4
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idfmax=idfbest+4
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idfstp=1
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ibmin=ibest-5
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ibmax=ibest+5
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ibstp=1
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endif
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ibest=-1
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smax=-99.
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idfbest=0
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call timer('sync4d ',0)
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do idf=idfmin,idfmax,idfstp
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do istart=ibmin,ibmax,ibstp
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call sync4d(cd2,istart,ctwk2(:,idf),1,sync) !Find sync power
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if(sync.gt.smax) then
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smax=sync
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ibest=istart
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idfbest=idf
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endif
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enddo
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enddo
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call timer('sync4d ',1)
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enddo
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f0=f0+real(idfbest)
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if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle
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call timer('ft4down ',0)
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call ft4_downsample(dd,dobigfft,f0,cb) !Final downsample, corrected f0
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call timer('ft4down ',1)
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sum2=sum(abs(cb)**2)/(real(NSS)*NN)
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if(sum2.gt.0.0) cb=cb/sqrt(sum2)
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cd=0.
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if(ibest.ge.0) then
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it=min(NDMAX-1,ibest+NN*NSS-1)
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np=it-ibest+1
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cd(0:np-1)=cb(ibest:it)
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else
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cd(-ibest:ibest+NN*NSS-1)=cb(0:NN*NSS+2*ibest-1)
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endif
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call timer('four2a ',0)
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do k=1,NN
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i1=(k-1)*NSS
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csymb=cd(i1:i1+NSS-1)
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call four2a(csymb,NSS,1,-1,1)
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cs(0:3,k)=csymb(1:4)
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s4(0:3,k)=abs(csymb(1:4))
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enddo
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call timer('four2a ',1)
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! Sync quality check
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is1=0
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is2=0
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is3=0
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is4=0
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do k=1,4
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ip=maxloc(s4(:,k))
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if(icos4a(k-1).eq.(ip(1)-1)) is1=is1+1
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ip=maxloc(s4(:,k+33))
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if(icos4b(k-1).eq.(ip(1)-1)) is2=is2+1
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ip=maxloc(s4(:,k+66))
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if(icos4c(k-1).eq.(ip(1)-1)) is3=is3+1
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ip=maxloc(s4(:,k+99))
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if(icos4d(k-1).eq.(ip(1)-1)) is4=is4+1
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enddo
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nsync=is1+is2+is3+is4 !Number of correct hard sync symbols, 0-16
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if(smax .lt. 0.7 .or. nsync .lt. 8) cycle
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do nseq=1,3 !Try coherent sequences of 1, 2, and 4 symbols
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if(nseq.eq.1) nsym=1
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if(nseq.eq.2) nsym=2
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if(nseq.eq.3) nsym=4
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nt=2**(2*nsym)
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do ks=1,NN-nsym+1,nsym !87+16=103 symbols.
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amax=-1.0
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do i=0,nt-1
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i1=i/64
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i2=iand(i,63)/16
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i3=iand(i,15)/4
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i4=iand(i,3)
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if(nsym.eq.1) then
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s2(i)=abs(cs(graymap(i4),ks))
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elseif(nsym.eq.2) then
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s2(i)=abs(cs(graymap(i3),ks)+cs(graymap(i4),ks+1))
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elseif(nsym.eq.4) then
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s2(i)=abs(cs(graymap(i1),ks ) + &
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cs(graymap(i2),ks+1) + &
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cs(graymap(i3),ks+2) + &
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cs(graymap(i4),ks+3) &
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)
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else
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print*,"Error - nsym must be 1, 2, or 4."
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endif
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enddo
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ipt=1+(ks-1)*2
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if(nsym.eq.1) ibmax=1
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if(nsym.eq.2) ibmax=3
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if(nsym.eq.4) ibmax=7
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do ib=0,ibmax
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bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
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maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
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if(ipt+ib.gt.2*NN) cycle
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if(nsym.eq.1) then
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bmeta(ipt+ib)=bm
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elseif(nsym.eq.2) then
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bmetb(ipt+ib)=bm
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elseif(nsym.eq.4) then
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bmetc(ipt+ib)=bm
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endif
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enddo
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enddo
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enddo
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bmetb(205:206)=bmeta(205:206)
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bmetc(201:204)=bmetb(201:204)
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bmetc(205:206)=bmeta(205:206)
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call normalizebmet(bmeta,2*NN)
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call normalizebmet(bmetb,2*NN)
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call normalizebmet(bmetc,2*NN)
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hbits=0
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where(bmeta.ge.0) hbits=1
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ns1=count(hbits( 1: 8).eq.(/0,0,0,1,1,0,1,1/))
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ns2=count(hbits( 67: 74).eq.(/0,1,0,0,1,1,1,0/))
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ns3=count(hbits(133:140).eq.(/1,1,1,0,0,1,0,0/))
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ns4=count(hbits(199:206).eq.(/1,0,1,1,0,0,0,1/))
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nsync_qual=ns1+ns2+ns3+ns4
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if(nsync_qual.lt. 20) cycle
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scalefac=2.83
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llra( 1: 58)=bmeta( 9: 66)
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llra( 59:116)=bmeta( 75:132)
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llra(117:174)=bmeta(141:198)
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llra=scalefac*llra
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llrb( 1: 58)=bmetb( 9: 66)
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llrb( 59:116)=bmetb( 75:132)
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llrb(117:174)=bmetb(141:198)
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llrb=scalefac*llrb
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llrc( 1: 58)=bmetc( 9: 66)
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llrc( 59:116)=bmetc( 75:132)
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llrc(117:174)=bmetc(141:198)
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llrc=scalefac*llrc
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apmag=maxval(abs(llra))*1.1
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npasses=3+nappasses(nQSOProgress)
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if(ndepth.eq.1) npasses=3
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if(ncontest.ge.5) npasses=3 ! Don't support Fox and Hound
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do ipass=1,npasses
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if(ipass.eq.1) llr=llra
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if(ipass.eq.2) llr=llrb
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if(ipass.eq.3) llr=llrc
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if(ipass.le.3) then
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apmask=0
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iaptype=0
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endif
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if(ipass .gt. 3) then
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llrd=llra
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iaptype=naptypes(nQSOProgress,ipass-3)
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! ncontest=0 : NONE
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! 1 : NA_VHF
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! 2 : EU_VHF
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! 3 : FIELD DAY
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! 4 : RTTY
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! 5 : FOX
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! 6 : HOUND
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!
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! Conditions that cause us to bail out of AP decoding
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napwid=50
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if(ncontest.le.4 .and. iaptype.ge.3 .and. (abs(f0-nfqso).gt.napwid) ) cycle
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if(iaptype.ge.2 .and. apbits(1).gt.1) cycle ! No, or nonstandard, mycall
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if(iaptype.ge.3 .and. apbits(30).gt.1) cycle ! No, or nonstandard, dxcall
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|
|
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if(iaptype.eq.1) then ! CQ or CQ TEST or CQ FD or CQ RU or CQ SCC
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|
apmask=0
|
|
apmask(1:29)=1
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|
llrd(1:29)=apmag*mcq(1:29)
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|
endif
|
|
|
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if(iaptype.eq.2) then ! MyCall,???,???
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|
apmask=0
|
|
if(ncontest.eq.0.or.ncontest.eq.1) then
|
|
apmask(1:29)=1
|
|
llrd(1:29)=apmag*apbits(1:29)
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|
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) 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 ! RTTY RU
|
|
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.4) then
|
|
apmask(1:91)=1 ! mycall, hiscall, RRR|73|RR73
|
|
if(iaptype.eq.6) llrd(1:91)=apmag*apbits(1:91)
|
|
endif
|
|
endif
|
|
|
|
llr=llrd
|
|
endif
|
|
message77=0
|
|
call timer('bpdec174',0)
|
|
call bpdecode174_91(llr,apmask,max_iterations,message77, &
|
|
cw,nharderror,niterations)
|
|
call timer('bpdec174',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(unpk77_success.and.dosubtract) then
|
|
call get_ft4_tones_from_77bits(message77,i4tone)
|
|
dt=real(ibest)/666.67
|
|
call timer('subtract',0)
|
|
call subtractft4(dd,i4tone,f0,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=-20.0
|
|
endif
|
|
nsnr=nint(max(-20.0,xsnr))
|
|
xdt=ibest/666.67 - 0.5
|
|
!write(21,'(i6.6,i5,2x,f4.1,i6,2x,a37,2x,f4.1,3i3)') nutc,nsnr,xdt,nint(f0),message,sync,iaptype,ipass,isp
|
|
call this%callback(sync,nsnr,xdt,f0,message,iaptype,qual)
|
|
exit
|
|
endif
|
|
enddo !Sequence estimation
|
|
enddo !Candidate list
|
|
enddo !Subtraction loop
|
|
return
|
|
end subroutine decode
|
|
|
|
end module ft4_decode
|