2012-05-22 17:09:48 +00:00
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program JT65code
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! Provides examples of message packing, bit and symbol ordering,
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! Reed Solomon encoding, and other necessary details of the JT65
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! protocol.
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character*22 msg0,msg,decoded,cok*3
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integer dgen(12),sent(63),recd(12),era(51)
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nargs=iargc()
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if(nargs.ne.1) then
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print*,'Usage: JT65code "message"'
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go to 999
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endif
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call getarg(1,msg0) !Get message from command line
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msg=msg0
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call chkmsg(msg,cok,nspecial,flip) !See if it includes "OOO" report
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if(nspecial.gt.0) then !or is a shorthand message
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write(*,1010)
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1010 format('Shorthand message.')
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go to 999
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endif
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call packmsg(msg,dgen) !Pack message into 72 bits
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write(*,1020) msg0
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1020 format('Message: ',a22) !Echo input message
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if(iand(dgen(10),8).ne.0) write(*,1030) !Is plain text bit set?
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1030 format('Plain text.')
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write(*,1040) dgen
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1040 format('Packed message, 6-bit symbols: ',12i3) !Display packed symbols
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call rs_encode(dgen,sent) !RS encode
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call interleave63(sent,1) !Interleave channel symbols
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call graycode(sent,63,1) !Apply Gray code
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write(*,1050) sent
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1050 format('Channel symbols, including FEC:'/(i5,20i3))
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call graycode(sent,63,-1)
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call interleave63(sent,-1)
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call rs_decode(sent,era,0,recd,nerr)
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call unpackmsg(recd,decoded) !Unpack the user message
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write(*,1060) decoded,cok
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1060 format('Decoded message: ',a22,2x,a3)
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999 end program JT65code
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