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https://github.com/saitohirga/WSJT-X.git
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4e37184f9e
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2607 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
118 lines
3.5 KiB
Fortran
118 lines
3.5 KiB
Fortran
subroutine genjt9(message,minutes,msgsent,d6)
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! Encodes a JT9 message and returns msgsent, the message as it will
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! be decoded, and an integer array d6(85) of 9-FSK tone values
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! in the range 0-8.
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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*4 mettab(0:255,0:1)
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integer*4 d0(13) !72-bit message as 6-bit words
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integer*1 d1(13) !72 bits and zero tail as 8-bit bytes
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integer*1 d2(207) !Encoded information-carrying bits
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integer*1 d3(207) !Bits from d2, after interleaving
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integer*4 d4(69) !Symbols from d3, values 0-7
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integer*4 d5(69) !Gray-coded symbols, values 0-7
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integer*4 d6(85) !Channel symbols including sync, values 0-8
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integer*4 t0(13) !72-bit message as 6-bit words
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integer*1 t1(13) !72 bits and zero tail as 8-bit bytes
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integer*1 t2(207) !Encoded information-carrying bits
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integer*1 t3(207) !Bits from t4, after interleaving
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integer*4 t4(69) !Symbols from t5, values 0-7
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integer*4 t5(69) !Gray-coded symbols, values 0-7
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integer*4 t6(85) !Channel symbols including sync, values 0-8
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integer*1 tmp(72)
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integer*1 i1
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equivalence (i1,i4)
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integer isync(85) !Sync vector
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data isync/ &
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1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0, &
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1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0, &
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0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0, &
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0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0, &
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1,0,0,0,1/
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save
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call packmsg(message,d0) !Pack message into 12 6-bit bytes
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call unpackmsg(d0,msgsent) !Unpack d0 to get msgsent
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call entail(d0,d1) !Add tail, convert to 8-bit bytes
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nsym2=206
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call encode232(d1,nsym2,d2) !Convolutional code, K=32, r=1/2
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call interleave9(d2,1,d3) !Interleave the single bits
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call packbits(d3,nsym2,3,d4) !Pack 3-bit groups into words
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call graycode(d4,69,1,d5) !Apply Gray code
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! Insert sync symbols (ntone=0) and add 1 to the data-tone numbers.
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j=0
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do i=1,85
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if(isync(i).eq.1) then
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d6(i)=0
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else
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j=j+1
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d6(i)=d5(j)+1
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endif
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enddo
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! We're done! Now reverse the process, as a test.
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t6=d6
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j=0
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do i=1,85
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if(isync(i).eq.1) cycle
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j=j+1
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t5(j)=t6(i)-1
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enddo
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call graycode(t5,69,-1,t4)
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call unpackbits(t4,69,3,t3)
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call interleave9(t3,-1,t2)
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! Get the metric table
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bias=0.37
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scale=10 !Optimize?
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open(19,file='met8.21',status='old')
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do i=0,255
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read(19,*) x00,x0,x1
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mettab(i,0)=nint(scale*(x0-bias))
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mettab(i,1)=nint(scale*(x1-bias)) !### Check range, etc. ###
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enddo
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close(19)
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nbits=72
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ndelta=17
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limit=1000
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do i=1,206
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i4=-10
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if(t2(i).eq.1) i4=10
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i4=i4+128
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t2(i)=i1
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enddo
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call fano232(t2,nbits+31,mettab,ndelta,limit,t1,ncycles,metric,ierr, &
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maxmetric,maxnp)
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nbytes=(nbits+7)/8
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do i=1,nbytes
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n=t1(i)
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t4(i)=iand(n,255)
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enddo
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call unpackbits(t4,nbytes,8,tmp)
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call packbits(tmp,12,6,t4)
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do i=1,12
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if(t4(i).lt.128) t1(i)=t4(i)
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if(t4(i).ge.128) t1(i)=t4(i)-256
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enddo
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do i=1,12
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t4(i)=t1(i)
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enddo
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print*,'z0',d0(1:12)-t4(1:12)
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return
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end subroutine genjt9
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