mirror of https://github.com/saitohirga/WSJT-X.git
Add some experimental routines.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7621 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Steven Franke
parent
4f2d3d08d0
commit
4565b182ff
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@ -309,6 +309,7 @@ set (wsjt_FSRCS
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lib/badmsg.f90
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lib/bpdecode40.f90
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lib/bpdecode144.f90
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lib/fsk4hf/bpdecode168.f90
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lib/baddata.f90
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lib/ccf2.f90
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lib/ccf65.f90
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@ -316,6 +317,7 @@ set (wsjt_FSRCS
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lib/chkmsg.f90
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lib/chkss2.f90
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lib/coord.f90
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lib/crc.f90
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lib/db.f90
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lib/decode4.f90
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lib/decode65a.f90
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@ -332,11 +334,13 @@ set (wsjt_FSRCS
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lib/encode4.f90
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lib/encode_msk40.f90
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lib/encode_msk144.f90
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lib/fsk4hf/encode168.f90
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lib/entail.f90
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lib/ephem.f90
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lib/extract.f90
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lib/extract4.f90
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lib/extractmessage144.f90
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lib/fsk4hf/extractmessage168.f90
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lib/fano232.f90
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lib/fast9.f90
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lib/fast_decode.f90
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@ -396,6 +400,7 @@ set (wsjt_FSRCS
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lib/jt9_decode.f90
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lib/jt9fano.f90
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lib/ldpcsim144.f90
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lib/fsk4hf/ldpcsim168.f90
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lib/ldpcsim40.f90
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lib/libration.f90
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lib/lorentzian.f90
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@ -1091,6 +1096,9 @@ target_link_libraries (ldpcsim40 wsjt_fort wsjt_cxx)
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add_executable (ldpcsim144 lib/ldpcsim144.f90 wsjtx.rc)
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target_link_libraries (ldpcsim144 wsjt_fort wsjt_cxx)
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add_executable (ldpcsim168 lib/fsk4hf/ldpcsim168.f90 lib/crc12.cpp wsjtx.rc)
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target_link_libraries (ldpcsim168 wsjt_fort wsjt_cxx)
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add_executable (msk144sim lib/msk144sim.f90 wsjtx.rc)
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target_link_libraries (msk144sim wsjt_fort wsjt_cxx)
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@ -0,0 +1,380 @@
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subroutine bpdecode168(llr,apmask,maxiterations,decoded,niterations)
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!
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! A log-domain belief propagation decoder for the (168,84) code.
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!
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integer, parameter:: N=168, K=84, M=N-K
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integer*1 codeword(N),cw(N),apmask(N)
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integer colorder(N)
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integer*1 decoded(K)
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integer Nm(7,M) ! 5, 6, or 7 bits per check
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integer Mn(3,N) ! 3 checks per bit
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integer synd(M)
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real tov(3,N)
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real toc(7,M)
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real tanhtoc(7,M)
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real zn(N)
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real llr(N)
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real Tmn
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integer nrw(M)
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data colorder/0,1,2,3,28,4,5,6,7,8,9,10,11,34,12,32,13,14,15,16,17, &
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18,36,29,42,31,20,21,41,40,30,38,22,19,47,37,46,35,44,33,49,24, &
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43,51,25,26,27,50,52,57,69,54,55,45,59,58,56,61,60,53,48,23,62, &
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63,64,67,66,65,68,39,70,71,72,74,73,75,76,77,80,81,78,82,79,83, &
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84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104, &
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105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125, &
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126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146, &
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147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167/
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data Mn/ &
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1,24,67, &
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2,5,71, &
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3,31,66, &
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4,50,58, &
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6,60,65, &
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7,32,76, &
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8,49,83, &
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9,36,41, &
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10,40,63, &
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11,14,62, &
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12,72,75, &
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13,23,78, &
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15,16,80, &
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17,54,64, &
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18,51,59, &
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19,30,48, &
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20,68,81, &
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21,29,70, &
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22,25,43, &
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26,34,73, &
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27,35,37, &
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28,39,44, &
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33,53,55, &
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38,52,84, &
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42,56,57, &
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45,74,82, &
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46,69,79, &
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47,61,77, &
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1,4,5, &
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2,48,52, &
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3,47,82, &
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6,26,76, &
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7,9,16, &
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8,10,78, &
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11,36,56, &
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12,38,65, &
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13,43,81, &
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14,33,68, &
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15,18,44, &
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17,59,77, &
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19,27,69, &
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20,21,58, &
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22,45,79, &
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23,34,54, &
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24,28,40, &
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25,80,84, &
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29,37,51, &
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30,42,83, &
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31,63,72, &
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32,50,66, &
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35,67,73, &
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39,55,74, &
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41,61,71, &
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46,60,62, &
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49,70,74, &
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53,64,75, &
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25,57,67, &
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1,46,64, &
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2,51,63, &
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3,14,80, &
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4,15,78, &
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5,27,74, &
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6,13,70, &
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7,19,20, &
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8,38,77, &
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9,75,83, &
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10,36,69, &
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11,22,29, &
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12,58,82, &
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16,35,60, &
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17,32,43, &
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18,42,45, &
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21,53,84, &
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23,39,48, &
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24,52,68, &
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26,33,61, &
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28,56,76, &
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30,65,66, &
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31,34,49, &
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37,47,81, &
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16,40,54, &
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41,44,65, &
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50,73,79, &
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55,59,60, &
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54,57,71, &
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23,62,72, &
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1,36,47, &
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2,32,70, &
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3,28,69, &
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4,7,33, &
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5,20,26, &
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6,14,63, &
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8,22,68, &
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9,13,67, &
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10,55,71, &
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11,15,19, &
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12,51,56, &
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17,27,52, &
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18,34,46, &
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21,41,42, &
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24,50,80, &
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25,39,75, &
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29,54,76, &
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30,40,84, &
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31,35,58, &
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37,79,83, &
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38,43,73, &
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44,72,81, &
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7,45,62, &
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47,48,49, &
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53,57,78, &
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20,59,66, &
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28,61,64, &
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11,75,77, &
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33,54,82, &
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1,14,44, &
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2,62,73, &
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3,9,26, &
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4,37,84, &
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5,56,80, &
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6,45,71, &
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8,67,72, &
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10,76,81, &
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12,32,78, &
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13,59,82, &
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15,17,79, &
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16,42,69, &
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18,61,70, &
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19,31,64, &
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21,39,63, &
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22,30,58, &
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23,27,66, &
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24,41,49, &
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25,36,60, &
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29,65,67, &
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34,36,53, &
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35,48,76, &
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15,38,55, &
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40,43,74, &
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46,52,57, &
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50,63,77, &
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51,68,69, &
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2,44,83, &
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1,30,55, &
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3,29,78, &
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4,34,65, &
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5,31,38, &
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6,52,58, &
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7,25,51, &
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8,16,66, &
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9,46,74, &
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10,70,75, &
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11,32,84, &
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12,48,79, &
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13,50,64, &
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14,37,57, &
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17,42,72, &
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18,43,48, &
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19,24,60, &
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20,54,83, &
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21,47,62, &
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22,28,59, &
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23,61,80, &
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8,26,39, &
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27,44,53, &
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33,49,56, &
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35,68,71, &
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12,26,40/
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data Nm/ &
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1,29,58,87,116,144,0,&
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2,30,59,88,117,143,0,&
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3,31,60,89,118,145,0,&
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4,29,61,90,119,146,0,&
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2,29,62,91,120,147,0,&
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5,32,63,92,121,148,0,&
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6,33,64,90,109,149,0,&
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7,34,65,93,122,150,164,&
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8,33,66,94,118,151,0,&
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9,34,67,95,123,152,0,&
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10,35,68,96,114,153,0,&
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11,36,69,97,124,154,168,&
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12,37,63,94,125,155,0,&
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10,38,60,92,116,156,0,&
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13,39,61,96,126,138,0,&
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13,33,70,81,127,150,0,&
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14,40,71,98,126,157,0,&
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15,39,72,99,128,158,0,&
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16,41,64,96,129,159,0,&
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17,42,64,91,112,160,0,&
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18,42,73,100,130,161,0,&
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19,43,68,93,131,162,0,&
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12,44,74,86,132,163,0,&
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1,45,75,101,133,159,0,&
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19,46,57,102,134,149,0,&
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20,32,76,91,118,164,168,&
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21,41,62,98,132,165,0,&
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22,45,77,89,113,162,0,&
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18,47,68,103,135,145,0,&
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16,48,78,104,131,144,0,&
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3,49,79,105,129,147,0,&
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6,50,71,88,124,153,0,&
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23,38,76,90,115,166,0,&
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20,44,79,99,136,146,0,&
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21,51,70,105,137,167,0,&
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8,35,67,87,134,136,0,&
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21,47,80,106,119,156,0,&
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24,36,65,107,138,147,0,&
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22,52,74,102,130,164,0,&
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9,45,81,104,139,168,0,&
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8,53,82,100,133,0,0,&
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25,48,72,100,127,157,0,&
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19,37,71,107,139,158,0,&
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22,39,82,108,116,143,165,&
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26,43,72,109,121,0,0,&
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27,54,58,99,140,151,0,&
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28,31,80,87,110,161,0,&
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16,30,74,110,137,154,158,&
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7,55,79,110,133,166,0,&
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4,50,83,101,141,155,0,&
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15,47,59,97,142,149,0,&
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24,30,75,98,140,148,0,&
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23,56,73,111,136,165,0,&
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14,44,81,85,103,115,160,&
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23,52,84,95,138,144,0,&
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25,35,77,97,120,166,0,&
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25,57,85,111,140,156,0,&
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4,42,69,105,131,148,0,&
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15,40,84,112,125,162,0,&
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5,54,70,84,134,159,0,&
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28,53,76,113,128,163,0,&
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10,54,86,109,117,161,0,&
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9,49,59,92,130,141,0,&
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14,56,58,113,129,155,0,&
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5,36,78,82,135,146,0,&
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3,50,78,112,132,150,0,&
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1,51,57,94,122,135,0,&
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17,38,75,93,142,167,0,&
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27,41,67,89,127,142,0,&
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18,55,63,88,128,152,0,&
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2,53,85,95,121,167,0,&
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11,49,86,108,122,157,0,&
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20,51,83,107,117,0,0,&
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26,52,55,62,139,151,0,&
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11,56,66,102,114,152,0,&
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6,32,77,103,123,137,0,&
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28,40,65,114,141,0,0,&
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12,34,61,111,124,145,0,&
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27,43,83,106,126,154,0,&
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13,46,60,101,120,163,0,&
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17,37,80,108,123,0,0,&
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26,31,69,115,125,0,0,&
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7,48,66,106,143,160,0,&
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24,46,73,104,119,153,0/
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data nrw/ &
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6,6,6,6,6,6,6,7,6,6,6,7,6,6,6,6,6,6,6,6,6, &
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6,6,6,6,7,6,6,6,6,6,6,6,6,6,6,6,6,6,6,5,6, &
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6,7,5,6,6,7,6,6,6,6,6,7,6,6,6,6,6,6,6,6,6, &
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6,6,6,6,6,6,6,6,6,5,6,6,6,5,6,6,6,5,5,6,6/
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ncw=3
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toc=0
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tov=0
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tanhtoc=0
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!write(*,*) llr
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! initialize messages to checks
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do j=1,M
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do i=1,nrw(j)
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toc(i,j)=llr((Nm(i,j)))
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enddo
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enddo
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ncnt=0
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do iter=0,maxiterations
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! Update bit log likelihood ratios (tov=0 in iteration 0).
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do i=1,N
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if( apmask(i) .ne. 1 ) then
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zn(i)=llr(i)+sum(tov(1:ncw,i))
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else
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zn(i)=llr(i)
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endif
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enddo
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! Check to see if we have a codeword (check before we do any iteration).
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cw=0
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where( zn .gt. 0. ) cw=1
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ncheck=0
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do i=1,M
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synd(i)=sum(cw(Nm(1:nrw(i),i)))
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if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
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! if( mod(synd(i),2) .ne. 0 ) write(*,*) 'check ',i,' unsatisfied'
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enddo
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!write(*,*) 'number of unsatisfied parity checks ',ncheck
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if( ncheck .eq. 0 ) then ! we have a codeword - reorder the columns and return it
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niterations=iter
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codeword=cw(colorder+1)
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decoded=codeword(M+1:N)
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return
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endif
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if( iter.gt.0 ) then ! this code block implements an early stopping criterion
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nd=ncheck-nclast
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if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
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ncnt=0 ! reset counter
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else
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ncnt=ncnt+1
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endif
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! write(*,*) iter,ncheck,nd,ncnt
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if( ncnt .ge. 3 .and. iter .ge. 5 .and. ncheck .gt. 10) then
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niterations=-1
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return
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endif
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endif
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nclast=ncheck
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! Send messages from bits to check nodes
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do j=1,M
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do i=1,nrw(j)
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ibj=Nm(i,j)
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toc(i,j)=zn(ibj)
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do kk=1,ncw ! subtract off what the bit had received from the check
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if( Mn(kk,ibj) .eq. j ) then
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toc(i,j)=toc(i,j)-tov(kk,ibj)
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endif
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enddo
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enddo
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enddo
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! send messages from check nodes to variable nodes
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do i=1,M
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tanhtoc(1:7,i)=tanh(-toc(1:7,i)/2)
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enddo
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do j=1,N
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do i=1,ncw
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ichk=Mn(i,j) ! Mn(:,j) are the checks that include bit j
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Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
|
||||
call platanh(-Tmn,y)
|
||||
! y=atanh(-Tmn)
|
||||
tov(i,j)=2*y
|
||||
enddo
|
||||
enddo
|
||||
|
||||
enddo
|
||||
niterations=-1
|
||||
return
|
||||
end subroutine bpdecode168
|
||||
|
|
@ -0,0 +1,141 @@
|
|||
subroutine encode168(message,codeword)
|
||||
! Encode an 84-bit message and return a 168-bit codeword.
|
||||
! The generator matrix has dimensions (84,84).
|
||||
! The code is a (168,84) regular ldpc code with column weight 3.
|
||||
! The code was generated using the PEG algorithm.
|
||||
! After creating the codeword, the columns are re-ordered according to
|
||||
! "colorder" to make the codeword compatible with the parity-check matrix
|
||||
!
|
||||
character*21 g(84)
|
||||
integer*1 codeword(168)
|
||||
integer colorder(168)
|
||||
integer*1 gen(84,168)
|
||||
integer*1 itmp(168)
|
||||
integer*1 message(84)
|
||||
integer*1 pchecks(84)
|
||||
logical first
|
||||
data first/.true./
|
||||
data g/ & !parity generator matrix for (168,84) code
|
||||
"25c5bf31ef6710fde9a5a", &
|
||||
"18038ef7899cd97a77d96", &
|
||||
"270dde504dad076c02b1f", &
|
||||
"ed37fe12616565bd7d500", &
|
||||
"12b99aa49b5367aff3838", &
|
||||
"41cc27f2fac8b228aac21", &
|
||||
"2265b233a3cff0b9cee24", &
|
||||
"292760cd4f7f4a526a2f1", &
|
||||
"2b3db4c8bd831911680cc", &
|
||||
"cef2b24ce203bdc60b266", &
|
||||
"5045a24f9340915d807ab", &
|
||||
"3592b7fc60ba85139502e", &
|
||||
"9318023145637bd798f0e", &
|
||||
"ad796023c3d58d1e6509c", &
|
||||
"3da5eab57f040e75d7413", &
|
||||
"27466d1d2734d0ff64830", &
|
||||
"2ed50bb1ce313bbfb1ab0", &
|
||||
"9a616bda01b25b7e6eeaf", &
|
||||
"a84c8c1e9df103169d10d", &
|
||||
"a40da29b4aca9234a8942", &
|
||||
"dd258d02d79a5f209d3d0", &
|
||||
"bdfdc06713511997b5621", &
|
||||
"25c58f12f4096cd8ead1a", &
|
||||
"b2638a478f21e10fe97de", &
|
||||
"4051020f43c605d458156", &
|
||||
"f651aad14322a526dae35", &
|
||||
"a1c147e31bcc9d87330bf", &
|
||||
"7524b53d996d48284647b", &
|
||||
"a72e7d25ce31b27282e56", &
|
||||
"a97f53b019022350b7519", &
|
||||
"56106c6340c0810790984", &
|
||||
"c63b8e03a57208635992b", &
|
||||
"43a3de2aa3a2b1afb65dc", &
|
||||
"9baa64847ead03b77fecc", &
|
||||
"251cbd1895c8839c46b0d", &
|
||||
"2858107dde2d173e13530", &
|
||||
"20096f6a870f636b704e7", &
|
||||
"7f833ccbceec52dd6eb79", &
|
||||
"a9108dd77b8015b75242a", &
|
||||
"689666a79e5579c916236", &
|
||||
"aa5dff46459787f69911f", &
|
||||
"794558c13138d08171089", &
|
||||
"c937042857b291cee8dfd", &
|
||||
"6f0bf3248bb9a231366b8", &
|
||||
"1c09e756ef1656c96f2d2", &
|
||||
"073b875b6774e71fba549", &
|
||||
"f7d840aafc037febd2d5c", &
|
||||
"dcc0e7d0da5fe17c99ad3", &
|
||||
"98238ef7819cd97a77d94", &
|
||||
"177c2594743477421a262", &
|
||||
"7d01a833c19374fbaaa6e", &
|
||||
"7bb800216660482ffd1c4", &
|
||||
"39a92e2dba0d4cfda98d2", &
|
||||
"44b8d88622698816456a8", &
|
||||
"791db2334d6d86639229b", &
|
||||
"ba6004b086bd38559ea48", &
|
||||
"f94558e13138d18170089", &
|
||||
"08ba145302cfbed7845ae", &
|
||||
"fb8e64b6da3602168ed38", &
|
||||
"1045a2cf1340915d8072b", &
|
||||
"7592b6fc64ba85139582e", &
|
||||
"3eb238a11bc6654452bae", &
|
||||
"b69d8d23b1ea170f70214", &
|
||||
"0123dfae84fb20462a614", &
|
||||
"4131066ad52a339b3c0d7", &
|
||||
"fd2cc26850951c43ed737", &
|
||||
"a644d4eb7e56c40f0d050", &
|
||||
"0c3bd9d5dab7c9ee2c8fc", &
|
||||
"4a198b37af56d7ceffb56", &
|
||||
"b6e946c429294cf0eed8b", &
|
||||
"98384d75e758774f5ff3b", &
|
||||
"5c58e5d9a4d0531d37384", &
|
||||
"7a0af02719afed521fd06", &
|
||||
"8cd5b2e694e7854abbc70", &
|
||||
"1a2f061912d0ea19702d3", &
|
||||
"6ffbce557d8fa691a50e8", &
|
||||
"d43438e2e2ed5d9f14011", &
|
||||
"8d502106083b809adba00", &
|
||||
"67e22f9b9983aa715964d", &
|
||||
"b31f3a3f3c1f406b1fd58", &
|
||||
"529f60ac291f827d97331", &
|
||||
"476a815424f2e2cbe641f", &
|
||||
"81c82c89bcc3feec42458", &
|
||||
"2c882d0e281b178e80364"/
|
||||
|
||||
data colorder/0,1,2,3,28,4,5,6,7,8,9,10,11,34,12,32,13,14,15,16,17, &
|
||||
18,36,29,42,31,20,21,41,40,30,38,22,19,47,37,46,35,44,33,49,24, &
|
||||
43,51,25,26,27,50,52,57,69,54,55,45,59,58,56,61,60,53,48,23,62, &
|
||||
63,64,67,66,65,68,39,70,71,72,74,73,75,76,77,80,81,78,82,79,83, &
|
||||
84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104, &
|
||||
105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125, &
|
||||
126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146, &
|
||||
147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167/
|
||||
|
||||
save first,gen
|
||||
|
||||
if( first ) then ! fill the generator matrix
|
||||
gen=0
|
||||
do i=1,84
|
||||
do j=1,21
|
||||
read(g(i)(j:j),"(Z1)") istr
|
||||
do jj=1, 4
|
||||
icol=(j-1)*4+jj
|
||||
if( btest(istr,4-jj) ) gen(i,icol)=1
|
||||
enddo
|
||||
enddo
|
||||
enddo
|
||||
first=.false.
|
||||
endif
|
||||
|
||||
do i=1, 84
|
||||
nsum=0
|
||||
do j=1, 84
|
||||
nsum=nsum+message(j)*gen(i,j)
|
||||
enddo
|
||||
pchecks(i)=mod(nsum,2)
|
||||
enddo
|
||||
itmp(1:84)=pchecks
|
||||
itmp(85:168)=message(1:84)
|
||||
codeword(colorder+1)=itmp(1:168)
|
||||
|
||||
return
|
||||
end subroutine encode168
|
||||
|
|
@ -0,0 +1,48 @@
|
|||
subroutine extractmessage168(decoded,msgreceived,ncrcflag,recent_calls,nrecent)
|
||||
use iso_c_binding, only: c_loc,c_size_t
|
||||
use crc
|
||||
use packjt
|
||||
|
||||
character*22 msgreceived
|
||||
character*12 call1,call2
|
||||
character*12 recent_calls(nrecent)
|
||||
integer*1 decoded(84)
|
||||
integer*1, target:: i1Dec8BitBytes(11)
|
||||
integer*4 i4Dec6BitWords(12)
|
||||
|
||||
! Collapse 84 decoded bits to 11 bytes. Bytes 1-9 are the message, byte 10 and first half of byte 11 is the crc
|
||||
do ibyte=1,9
|
||||
itmp=0
|
||||
do ibit=1,8
|
||||
itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*8+ibit))
|
||||
enddo
|
||||
i1Dec8BitBytes(ibyte)=itmp
|
||||
enddo
|
||||
! Need to pack the crc into bytes 10 and 11 for crc12_check
|
||||
i1Dec8BitBytes(10)=decoded(73)*8+decoded(74)*4+decoded(75)*2+decoded(76)
|
||||
i1Dec8BitBytes(11)=decoded(77)*128+decoded(78)*64+decoded(79)*2*32+decoded(80)*16
|
||||
i1Dec8BitBytes(11)=i1Dec8BitBytes(11)+decoded(81)*8+decoded(82)*4+decoded(83)*2+decoded(84)
|
||||
|
||||
if( crc12_check(c_loc (i1Dec8BitBytes), 11) ) then
|
||||
! CRC12 checks out --- unpack 72-bit message
|
||||
do ibyte=1,12
|
||||
itmp=0
|
||||
do ibit=1,6
|
||||
itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*6+ibit))
|
||||
enddo
|
||||
i4Dec6BitWords(ibyte)=itmp
|
||||
enddo
|
||||
call unpackmsg144(i4Dec6BitWords,msgreceived,call1,call2)
|
||||
ncrcflag=1
|
||||
if( call1(1:2) .ne. 'CQ' .and. call1(1:2) .ne. ' ' ) then
|
||||
call update_recent_calls(call1,recent_calls,nrecent)
|
||||
endif
|
||||
if( call2(1:2) .ne. ' ' ) then
|
||||
call update_recent_calls(call2,recent_calls,nrecent)
|
||||
endif
|
||||
else
|
||||
msgreceived=' '
|
||||
ncrcflag=-1
|
||||
endif
|
||||
return
|
||||
end subroutine extractmessage168
|
||||
|
|
@ -0,0 +1,219 @@
|
|||
program ldpcsim168
|
||||
! End to end test of the (168,84)/crc12 encoder and decoder.
|
||||
use crc
|
||||
use packjt
|
||||
|
||||
parameter(NRECENT=10)
|
||||
character*12 recent_calls(NRECENT)
|
||||
character*22 msg,msgsent,msgreceived
|
||||
character*8 arg
|
||||
integer*1, allocatable :: codeword(:), decoded(:), message(:)
|
||||
integer*1, target:: i1Msg8BitBytes(11)
|
||||
integer*1 msgbits(84)
|
||||
integer*1 apmask(168)
|
||||
integer*2 checksum
|
||||
integer*4 i4Msg6BitWords(13)
|
||||
integer colorder(168)
|
||||
integer nerrtot(168),nerrdec(168)
|
||||
logical checksumok,fsk,bpsk
|
||||
real*8, allocatable :: rxdata(:)
|
||||
real, allocatable :: llr(:)
|
||||
|
||||
data colorder/0,1,2,3,28,4,5,6,7,8,9,10,11,34,12,32,13,14,15,16,17, &
|
||||
18,36,29,42,31,20,21,41,40,30,38,22,19,47,37,46,35,44,33,49,24, &
|
||||
43,51,25,26,27,50,52,57,69,54,55,45,59,58,56,61,60,53,48,23,62, &
|
||||
63,64,67,66,65,68,39,70,71,72,74,73,75,76,77,80,81,78,82,79,83, &
|
||||
84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104, &
|
||||
105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125, &
|
||||
126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146, &
|
||||
147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167/
|
||||
|
||||
do i=1,NRECENT
|
||||
recent_calls(i)=' '
|
||||
enddo
|
||||
nerrtot=0
|
||||
nerrdec=0
|
||||
|
||||
nargs=iargc()
|
||||
if(nargs.ne.3) then
|
||||
print*,'Usage: ldpcsim niter #trials s '
|
||||
print*,'eg: ldpcsim 10 1000 0.75'
|
||||
return
|
||||
endif
|
||||
call getarg(1,arg)
|
||||
read(arg,*) max_iterations
|
||||
call getarg(2,arg)
|
||||
read(arg,*) ntrials
|
||||
call getarg(3,arg)
|
||||
read(arg,*) s
|
||||
|
||||
fsk=.true.
|
||||
bpsk=.false.
|
||||
|
||||
! don't count crc bits as data bits
|
||||
N=168
|
||||
K=84
|
||||
! scale Eb/No for a (168,72) code
|
||||
rate=real(72)/real(N)
|
||||
|
||||
write(*,*) "rate: ",rate
|
||||
write(*,*) "niter= ",max_iterations," s= ",s
|
||||
|
||||
allocate ( codeword(N), decoded(K), message(K) )
|
||||
allocate ( rxdata(N), llr(N) )
|
||||
|
||||
msg="K1JT K9AN EN50"
|
||||
call packmsg(msg,i4Msg6BitWords,itype) !Pack into 12 6-bit bytes
|
||||
call unpackmsg(i4Msg6BitWords,msgsent) !Unpack to get msgsent
|
||||
write(*,*) "message sent ",msgsent
|
||||
|
||||
i4=0
|
||||
ik=0
|
||||
im=0
|
||||
do i=1,12
|
||||
nn=i4Msg6BitWords(i)
|
||||
do j=1, 6
|
||||
ik=ik+1
|
||||
i4=i4+i4+iand(1,ishft(nn,j-6))
|
||||
i4=iand(i4,255)
|
||||
if(ik.eq.8) then
|
||||
im=im+1
|
||||
! if(i4.gt.127) i4=i4-256
|
||||
i1Msg8BitBytes(im)=i4
|
||||
ik=0
|
||||
endif
|
||||
enddo
|
||||
enddo
|
||||
|
||||
i1Msg8BitBytes(10:11)=0
|
||||
checksum = crc12 (c_loc (i1Msg8BitBytes), 11)
|
||||
! For reference, the next 3 lines show how to check the CRC
|
||||
i1Msg8BitBytes(10)=checksum/256
|
||||
i1Msg8BitBytes(11)=iand (checksum,255)
|
||||
checksumok = crc12_check(c_loc (i1Msg8BitBytes), 11)
|
||||
if( checksumok ) write(*,*) 'Good checksum'
|
||||
|
||||
mbit=0
|
||||
do i=1, 9
|
||||
i1=i1Msg8BitBytes(i)
|
||||
do ibit=1,8
|
||||
mbit=mbit+1
|
||||
msgbits(mbit)=iand(1,ishft(i1,ibit-8))
|
||||
enddo
|
||||
enddo
|
||||
i1=i1Msg8BitBytes(10) ! First 4 bits of crc12 are LSB of this byte
|
||||
do ibit=1,4
|
||||
msgbits(72+ibit)=iand(1,ishft(i1,ibit-4))
|
||||
enddo
|
||||
i1=i1Msg8BitBytes(11) ! Now shift in last 8 bits of the CRC
|
||||
do ibit=1,8
|
||||
msgbits(76+ibit)=iand(1,ishft(i1,ibit-8))
|
||||
enddo
|
||||
|
||||
write(*,*) 'message'
|
||||
write(*,'(11(8i1,1x))') msgbits
|
||||
|
||||
call encode168(msgbits,codeword)
|
||||
call init_random_seed()
|
||||
call sgran()
|
||||
|
||||
write(*,*) 'codeword'
|
||||
write(*,'(21(8i1,1x))') codeword
|
||||
|
||||
write(*,*) "Es/N0 SNR2500 ngood nundetected nbadcrc sigma"
|
||||
do idb = -10, 24
|
||||
db=idb/2.0-1.0
|
||||
! sigma=1/sqrt( 2*rate*(10**(db/10.0)) )
|
||||
sigma=1/sqrt( 2*(10**(db/10.0)) )
|
||||
ngood=0
|
||||
nue=0
|
||||
nbadcrc=0
|
||||
nberr=0
|
||||
do itrial=1, ntrials
|
||||
! Create a realization of a noisy received word
|
||||
do i=1,N
|
||||
if( bpsk ) then
|
||||
rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
|
||||
elseif( fsk ) then
|
||||
if( codeword(i) .eq. 1 ) then
|
||||
r1=(1.0 + sigma*gran())**2 + (sigma*gran())**2
|
||||
r2=(sigma*gran())**2 + (sigma*gran())**2
|
||||
elseif( codeword(i) .eq. 0 ) then
|
||||
r2=(1.0 + sigma*gran())**2 + (sigma*gran())**2
|
||||
r1=(sigma*gran())**2 + (sigma*gran())**2
|
||||
endif
|
||||
rxdata(i)=0.35*(sqrt(r1)-sqrt(r2))
|
||||
! rxdata(i)=0.35*(exp(r1)-exp(r2))
|
||||
! rxdata(i)=0.12*(log(r1)-log(r2))
|
||||
endif
|
||||
enddo
|
||||
nerr=0
|
||||
do i=1,N
|
||||
if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
|
||||
enddo
|
||||
nerrtot(nerr)=nerrtot(nerr)+1
|
||||
nberr=nberr+nerr
|
||||
|
||||
! Correct signal normalization is important for this decoder.
|
||||
! rxav=sum(rxdata)/N
|
||||
! rx2av=sum(rxdata*rxdata)/N
|
||||
! rxsig=sqrt(rx2av-rxav*rxav)
|
||||
! rxdata=rxdata/rxsig
|
||||
! To match the metric to the channel, s should be set to the noise standard deviation.
|
||||
! For now, set s to the value that optimizes decode probability near threshold.
|
||||
! The s parameter can be tuned to trade a few tenth's dB of threshold for an order of
|
||||
! magnitude in UER
|
||||
if( s .lt. 0 ) then
|
||||
ss=sigma
|
||||
else
|
||||
ss=s
|
||||
endif
|
||||
|
||||
llr=2.0*rxdata/(ss*ss)
|
||||
nap=0 ! number of AP bits
|
||||
llr(colorder(168-84+1:168-84+nap)+1)=5*(2.0*msgbits(1:nap)-1.0)
|
||||
apmask=0
|
||||
apmask(colorder(168-84+1:168-84+nap)+1)=1
|
||||
|
||||
! max_iterations is max number of belief propagation iterations
|
||||
call bpdecode168(llr, apmask, max_iterations, decoded, niterations)
|
||||
! If the decoder finds a valid codeword, niterations will be .ge. 0.
|
||||
if( niterations .ge. 0 ) then
|
||||
call extractmessage168(decoded,msgreceived,ncrcflag,recent_calls,nrecent)
|
||||
if( ncrcflag .eq. 1 ) then
|
||||
ncrcflag=1
|
||||
else
|
||||
ncrcflag=0
|
||||
endif
|
||||
if( ncrcflag .ne. 1 ) then
|
||||
nbadcrc=nbadcrc+1
|
||||
endif
|
||||
nueflag=0
|
||||
|
||||
! Check the message plus crc against what was sent.
|
||||
do i=1,K
|
||||
if( msgbits(i) .ne. decoded(i) ) then
|
||||
nueflag=1
|
||||
endif
|
||||
enddo
|
||||
if( ncrcflag .eq. 1 .and. nueflag .eq. 0 ) then
|
||||
ngood=ngood+1
|
||||
nerrdec(nerr)=nerrdec(nerr)+1
|
||||
else if( ncrcflag .eq. 1 .and. nueflag .eq. 1 ) then
|
||||
nue=nue+1;
|
||||
endif
|
||||
endif
|
||||
enddo
|
||||
snr2500=db+10*log10(8.333/2500.0)
|
||||
pberr=real(nberr)/(real(ntrials*N))
|
||||
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
|
||||
|
||||
enddo
|
||||
|
||||
open(unit=23,file='nerrhisto.dat',status='unknown')
|
||||
do i=1,128
|
||||
write(23,'(i4,2x,i10,i10,f10.2)') i,nerrdec(i),nerrtot(i),real(nerrdec(i))/real(nerrtot(i)+1e-10)
|
||||
enddo
|
||||
close(23)
|
||||
|
||||
end program ldpcsim168
|
||||
Loading…
Reference in New Issue