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b048669c02
------------------------------------------------------------------------ r8060 | k1jt | 2017-09-01 13:51:42 +0100 (Fri, 01 Sep 2017) | 2 lines Add a link to G3WDG doc on using QRA64 for microwave EME. ------------------------------------------------------------------------ r8061 | k1jt | 2017-09-01 17:22:19 +0100 (Fri, 01 Sep 2017) | 1 line Fix a misspelled word. ------------------------------------------------------------------------ r8062 | bsomervi | 2017-09-01 21:10:35 +0100 (Fri, 01 Sep 2017) | 7 lines Rationalize NA contest mode Generic message packing and unpacking routines now understand antipode grid contest messages. These messages are now recognized as standard messages in message response processing and dealt with appropriately when contest mode is selected and applicable (currently FT8 and MSK144 only). ------------------------------------------------------------------------ r8063 | bsomervi | 2017-09-01 21:43:45 +0100 (Fri, 01 Sep 2017) | 1 line Fix issue compiling with Qt older than v5.7 ------------------------------------------------------------------------ r8064 | bsomervi | 2017-09-01 22:29:02 +0100 (Fri, 01 Sep 2017) | 7 lines Fix issues with type 2 compound calls in contest mode Message generation in contest mode now generates the correct Tx3 for type 2 calls. "<type-2> 73" is a free text so needed special handling in message processing. ------------------------------------------------------------------------ r8065 | bsomervi | 2017-09-01 23:22:20 +0100 (Fri, 01 Sep 2017) | 11 lines Improved message generation for type 2 calls in contest mode These attempt to ensure that a prefix is logged by the QSO partner even if the compound call holder user Tx3 to tail-end a QSO. The type 2 message generation options are largely overridden in contest mode as only a few options make sense. Key is that Tx1 may use only the base call when calling split is necessary, this requires that both Tx3 and Tx4 have the full compound call otherwise the QSO partner will never see the full call until it is possibly too late i.e. post logging. ------------------------------------------------------------------------ r8066 | bsomervi | 2017-09-02 00:28:44 +0100 (Sat, 02 Sep 2017) | 5 lines Fix erroneous auto stop critera for auto reply in FT8 We cannot assume that a "DE <dx-call> <anything>" is or is not for us so we must continue calling and risk possible QRM. Calling split avoids this issue. ------------------------------------------------------------------------ git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx-1.8@8067 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
239 lines
7.0 KiB
Fortran
239 lines
7.0 KiB
Fortran
program ldpcsim174
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! End to end test of the (174,75)/crc12 encoder and decoder.
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use crc
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use packjt
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parameter(NRECENT=10)
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character*12 recent_calls(NRECENT)
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character*22 msg,msgsent,msgreceived
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character*8 arg
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integer*1, allocatable :: codeword(:), decoded(:), message(:)
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integer*1, target:: i1Msg8BitBytes(11)
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integer*1 msgbits(87)
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integer*1 apmask(174), cw(174)
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integer*2 checksum
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integer*4 i4Msg6BitWords(13)
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integer colorder(174)
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integer nerrtot(174),nerrdec(174),nmpcbad(87)
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logical checksumok,fsk,bpsk
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real*8, allocatable :: rxdata(:)
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real, allocatable :: llr(:)
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data colorder/ &
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0, 1, 2, 3, 30, 4, 5, 6, 7, 8, 9, 10, 11, 32, 12, 40, 13, 14, 15, 16,&
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17, 18, 37, 45, 29, 19, 20, 21, 41, 22, 42, 31, 33, 34, 44, 35, 47, 51, 50, 43,&
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36, 52, 63, 46, 25, 55, 27, 24, 23, 53, 39, 49, 59, 38, 48, 61, 60, 57, 28, 62,&
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56, 58, 65, 66, 26, 70, 64, 69, 68, 67, 74, 71, 54, 76, 72, 75, 78, 77, 80, 79,&
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73, 83, 84, 81, 82, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99,&
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100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,&
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120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,&
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140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,&
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160,161,162,163,164,165,166,167,168,169,170,171,172,173/
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do i=1,NRECENT
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recent_calls(i)=' '
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enddo
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nerrtot=0
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nerrdec=0
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nmpcbad=0 ! Used to collect the number of errors in the message+crc part of the codeword
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nargs=iargc()
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if(nargs.ne.4) then
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print*,'Usage: ldpcsim niter ndepth #trials s '
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print*,'eg: ldpcsim 10 2 1000 0.84'
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print*,'belief propagation iterations: niter, ordered-statistics depth: ndepth'
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print*,'If s is negative, then value is ignored and sigma is calculated from SNR.'
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return
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endif
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call getarg(1,arg)
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read(arg,*) max_iterations
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call getarg(2,arg)
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read(arg,*) ndepth
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call getarg(3,arg)
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read(arg,*) ntrials
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call getarg(4,arg)
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read(arg,*) s
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fsk=.false.
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bpsk=.true.
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! don't count crc bits as data bits
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N=174
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K=87
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! scale Eb/No for a (174,87) code
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rate=real(K)/real(N)
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write(*,*) "rate: ",rate
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write(*,*) "niter= ",max_iterations," s= ",s
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allocate ( codeword(N), decoded(K), message(K) )
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allocate ( rxdata(N), llr(N) )
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msg="K1JT K9AN EN50"
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! msg="G4WJS K9AN EN50"
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call packmsg(msg,i4Msg6BitWords,itype,.false.) !Pack into 12 6-bit bytes
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call unpackmsg(i4Msg6BitWords,msgsent,.false.,'') !Unpack to get msgsent
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write(*,*) "message sent ",msgsent
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i4=0
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ik=0
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im=0
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do i=1,12
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nn=i4Msg6BitWords(i)
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do j=1, 6
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ik=ik+1
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i4=i4+i4+iand(1,ishft(nn,j-6))
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i4=iand(i4,255)
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if(ik.eq.8) then
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im=im+1
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! if(i4.gt.127) i4=i4-256
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i1Msg8BitBytes(im)=i4
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ik=0
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endif
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enddo
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enddo
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i1Msg8BitBytes(10:11)=0
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checksum = crc12 (c_loc (i1Msg8BitBytes), 11)
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! For reference, the next 3 lines show how to check the CRC
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i1Msg8BitBytes(10)=checksum/256
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i1Msg8BitBytes(11)=iand (checksum,255)
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checksumok = crc12_check(c_loc (i1Msg8BitBytes), 11)
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if( checksumok ) write(*,*) 'Good checksum'
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! K=87, For now:
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! msgbits(1:72) JT message bits
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! msgbits(73:75) 3 free message bits (set to 0)
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! msgbits(76:87) CRC12
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mbit=0
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do i=1, 9
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i1=i1Msg8BitBytes(i)
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do ibit=1,8
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mbit=mbit+1
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msgbits(mbit)=iand(1,ishft(i1,ibit-8))
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enddo
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enddo
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msgbits(73:75)=0 ! the three extra message bits go here
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i1=i1Msg8BitBytes(10) ! First 4 bits of crc12 are LSB of this byte
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do ibit=1,4
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msgbits(75+ibit)=iand(1,ishft(i1,ibit-4))
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enddo
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i1=i1Msg8BitBytes(11) ! Now shift in last 8 bits of the CRC
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do ibit=1,8
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msgbits(79+ibit)=iand(1,ishft(i1,ibit-8))
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enddo
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write(*,*) 'message'
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write(*,'(11(8i1,1x))') msgbits
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call encode174(msgbits,codeword)
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call init_random_seed()
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! call sgran()
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write(*,*) 'codeword'
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write(*,'(22(8i1,1x))') codeword
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write(*,*) "Es/N0 SNR2500 ngood nundetected nbadcrc sigma"
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do idb = 20,-10,-1
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!do idb = -3,-3,-1
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db=idb/2.0-1.0
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sigma=1/sqrt( 2*(10**(db/10.0)) )
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ngood=0
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nue=0
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nbadcrc=0
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nberr=0
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do itrial=1, ntrials
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! Create a realization of a noisy received word
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do i=1,N
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if( bpsk ) then
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rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
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elseif( fsk ) then
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if( codeword(i) .eq. 1 ) then
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r1=(1.0 + sigma*gran())**2 + (sigma*gran())**2
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r2=(sigma*gran())**2 + (sigma*gran())**2
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elseif( codeword(i) .eq. 0 ) then
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r2=(1.0 + sigma*gran())**2 + (sigma*gran())**2
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r1=(sigma*gran())**2 + (sigma*gran())**2
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endif
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! rxdata(i)=0.35*(sqrt(r1)-sqrt(r2))
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! rxdata(i)=0.35*(exp(r1)-exp(r2))
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rxdata(i)=0.12*(log(r1)-log(r2))
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endif
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enddo
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nerr=0
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do i=1,N
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if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
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enddo
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nerrtot(nerr)=nerrtot(nerr)+1
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nberr=nberr+nerr
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! Correct signal normalization is important for this decoder.
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rxav=sum(rxdata)/N
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rx2av=sum(rxdata*rxdata)/N
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rxsig=sqrt(rx2av-rxav*rxav)
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rxdata=rxdata/rxsig
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! To match the metric to the channel, s should be set to the noise standard deviation.
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! For now, set s to the value that optimizes decode probability near threshold.
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! The s parameter can be tuned to trade a few tenth's dB of threshold for an order of
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! magnitude in UER
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if( s .lt. 0 ) then
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ss=sigma
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else
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ss=s
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endif
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llr=2.0*rxdata/(ss*ss)
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nap=0 ! number of AP bits
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llr(colorder(174-87+1:174-87+nap)+1)=5*(2.0*msgbits(1:nap)-1.0)
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apmask=0
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apmask(colorder(174-87+1:174-87+nap)+1)=1
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! max_iterations is max number of belief propagation iterations
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call bpdecode174(llr, apmask, max_iterations, decoded, cw, nharderrors,niterations)
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if( ndepth .ge. 0 .and. nharderrors .lt. 0 ) call osd174(llr, apmask, ndepth, decoded, cw, nharderrors, dmin)
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! If the decoder finds a valid codeword, nharderrors will be .ge. 0.
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if( nharderrors .ge. 0 ) then
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call extractmessage174(decoded,msgreceived,ncrcflag,recent_calls,nrecent)
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if( ncrcflag .ne. 1 ) then
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nbadcrc=nbadcrc+1
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endif
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nueflag=0
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nerrmpc=0
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do i=1,K ! find number of errors in message+crc part of codeword
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if( msgbits(i) .ne. decoded(i) ) then
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nueflag=1
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nerrmpc=nerrmpc+1
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endif
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enddo
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nmpcbad(nerrmpc)=nmpcbad(nerrmpc)+1
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if( ncrcflag .eq. 1 ) then
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if( nueflag .eq. 0 ) then
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ngood=ngood+1
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nerrdec(nerr)=nerrdec(nerr)+1
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else if( nueflag .eq. 1 ) then
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nue=nue+1;
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endif
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endif
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endif
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enddo
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baud=12000/1920
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snr2500=db+10.0*log10((baud/2500.0))
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pberr=real(nberr)/(real(ntrials*N))
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write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,snr2500,ngood,nue,nbadcrc,ss,pberr
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enddo
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open(unit=23,file='nerrhisto.dat',status='unknown')
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do i=1,174
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write(23,'(i4,2x,i10,i10,f10.2)') i,nerrdec(i),nerrtot(i),real(nerrdec(i))/real(nerrtot(i)+1e-10)
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enddo
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close(23)
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open(unit=25,file='nmpcbad.dat',status='unknown')
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do i=1,87
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write(25,'(i4,2x,i10)') i,nmpcbad(i)
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enddo
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close(25)
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end program ldpcsim174
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