2021-04-09 08:57:41 -04:00
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subroutine genqra64a(msg0,ichk,ntxfreq,mode64,itype,msgsent,iwave,nwave)
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! Encodes a QRA64 message to yield itone(1:84)
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use packjt
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parameter (NMAX=2*60*11025)
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character*22 msg0
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character*22 message !Message to be generated
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character*22 msgsent !Message as it will be received
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integer itone(84)
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character*3 cok !' ' or 'OOO'
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real*8 t,dt,phi,f,f0,dfgen,dphi,twopi,samfac,tsym
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integer dgen(13)
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integer sent(63)
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integer*2 iwave(NMAX)
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integer icos7(0:6)
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data icos7/2,5,6,0,4,1,3/ !Defines a 7x7 Costas array
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data twopi/6.283185307179586476d0/
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save
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if(msg0(1:1).eq.'@') then
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read(msg0(2:5),*,end=1,err=1) nfreq
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go to 2
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1 nfreq=1000
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2 itone(1)=nfreq
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write(msgsent,1000) nfreq
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1000 format(i5,' Hz')
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else
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message=msg0
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do i=1,22
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if(ichar(message(i:i)).eq.0) then
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message(i:)=' '
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exit
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endif
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enddo
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do i=1,22 !Strip leading blanks
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if(message(1:1).ne.' ') exit
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message=message(i+1:)
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enddo
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call chkmsg(message,cok,nspecial,flip)
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call packmsg(message,dgen,itype) !Pack message into 72 bits
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call unpackmsg(dgen,msgsent) !Unpack to get message sent
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if(ichk.ne.0) go to 999 !Return if checking only
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call qra64_enc(dgen,sent) !Encode using QRA64
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nsync=10
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itone(1:7)=nsync*icos7 !Insert 7x7 Costas array in 3 places
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itone(8:39)=sent(1:32)
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itone(40:46)=nsync*icos7
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itone(47:77)=sent(33:63)
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itone(78:84)=nsync*icos7
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endif
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! Set up necessary constants
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nsym=84
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tsym=6912.d0/12000.d0
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samfac=1.d0
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dt=1.d0/(samfac*11025.d0)
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f0=ntxfreq
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ndf=2**(mode64-1)
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dfgen=ndf*12000.d0/6912.d0
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phi=0.d0
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dphi=twopi*dt*f0
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i=0
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iz=84*6912*11025.d0/12000.d0
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t=0.d0
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j0=0
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do i=1,iz
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t=t+dt
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j=t/tsym
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if(j.ne.j0) then
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f=f0 + itone(j)*dfgen
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dphi=twopi*dt*f
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j0=j
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endif
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phi=phi+dphi
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if(phi.gt.twopi) phi=phi-twopi
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xphi=phi
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iwave(2*i-1)=32767.0*cos(xphi)
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iwave(2*i)=32767.0*sin(xphi)
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enddo
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nwave=2*iz
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999 return
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end subroutine genqra64a
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