subroutine encode300(message,codeword)
! Encode an 60-bit message and return a 300-bit codeword. 
! The generator matrix has dimensions (240,60). 
! The code is a (300,60) irregular ldpc code with column weights:
!   52% column weight 2
!   27% column weight 3
!   21% column weight 7 
! 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*15 g(240)
integer*1 codeword(300)
integer colorder(300)
integer*1 gen(240,60)
integer*1 itmp(300)
integer*1 message(60)
integer*1 pchecks(240)
logical first
data first/.true./
data g/            &
 "316fd3bb18bcefd", &
 "a9c1c984f91244e", &
 "9e04bd3d5d78d89", &
 "f81617089621bd4", &
 "12997ce2f44dbf4", &
 "3ebddaf9b0fa1fc", &
 "d0c114b0b0ef162", &
 "f8c4f115f98bd92", &
 "d0a79c0c5b8ca19", &
 "477f6712f357b3b", &
 "fa28b2444a7e66b", &
 "bedcd4df8d95c64", &
 "da30de73e57022c", &
 "bc099bbb90fe09e", &
 "cffc1e47e5708e8", &
 "713d808563ca9a3", &
 "70fcf1741d5d5d7", &
 "32e80bc15112008", &
 "804cef4df9b18ec", &
 "3736881819d1033", &
 "f4e37db7f9c5efe", &
 "9e84b93d4d78d09", &
 "2250c3518ec830a", &
 "55a529a92e18021", &
 "1cb80b14c9f6eae", &
 "80c504b031ef926", &
 "ece6636d0ac9c6d", &
 "5d50a1690782cd0", &
 "3d54a1fb30937a2", &
 "ba8fe8006318041", &
 "02917ce2fc45bf4", &
 "abc1d984f95a44e", &
 "fc05b4c4ab2d850", &
 "467f7718f357b3b", &
 "472cc094546c6b2", &
 "fcdd94cf8c9cc64", &
 "4dbc1647e970cc8", &
 "6caa465c442aed1", &
 "aead5af8b0da1be", &
 "d8e1fa45a2e8431", &
 "9d4dc4cc63abb7f", &
 "9b2df6b48264637", &
 "7335808563ca3a3", &
 "36bf8d5cd93e6cc", &
 "004ccf4db9b08ec", &
 "90a71c8c598ca19", &
 "f8c5d115f90bc92", &
 "b95546c4e3f7934", &
 "7d50a1690786cd0", &
 "c90939921a0d7c6", &
 "d0c504b030ef126", &
 "ce3e6f9396fc542", &
 "a0072a59f3707f5", &
 "532d0a8fe3da1ea", &
 "68b9e5cd7d142db", &
 "fedc94df8c9dc64", &
 "6da2465c448aed0", &
 "3574aa19cb273c0", &
 "1e54768c6bc6843", &
 "691f65654498186", &
 "fe2c92444a6ef6b", &
 "9caad933e038cc4", &
 "ad4e6f4defb28ec", &
 "4f3d80947c6d2b2", &
 "1caad933e0b8cc4", &
 "b14fd3bf18bcafd", &
 "ad091bbbb0f809e", &
 "90b71c8c598da19", &
 "f8c4d115f90bd92", &
 "9d4dcccc63afb7f", &
 "fa2c92444a6e76b", &
 "1e14768c6bc6c43", &
 "d1baf5aacb86087", &
 "bdf762b92ee51c7", &
 "caacec06ad8a90c", &
 "804ccf4df9b08ec", &
 "69e969f9da5cbd8", &
 "814ccf4df9b086c", &
 "cebe4f9796f4542", &
 "491f65654499186", &
 "8fbf5b9796f6d2a", &
 "ce3e4f9396f4542", &
 "47558560e7debc3", &
 "94aadd33e038cc4", &
 "a94eef4debb286e", &
 "d8e5d115f91bcd2", &
 "532d488fe3da0ab", &
 "664e7bc4e23a80c", &
 "94a2dd33a038cd4", &
 "d8c5d115f91bc92", &
 "0fef071eee60bd5", &
 "9a89a09163c2b97", &
 "0eaf071e6c60bd5", &
 "bc0d1bbbb0fe0be", &
 "f9babd3d12d0f31", &
 "69a969f9da5c9d8", &
 "6e4e7bc4e23a82c", &
 "b0042659f3227f5", &
 "2d51418f0f28347", &
 "be0d5bbbb0da0be", &
 "225003508ec8302", &
 "8fbf4b9796f4d2a", &
 "bead5af9b0da1be", &
 "6ca2465c440aed1", &
 "4fbc1e47ed708c8", &
 "bd091bbbb0fc09e", &
 "b0062259f3307f5", &
 "a8072a59f3727f5", &
 "a0062259f3707f5", &
 "3c380b14c974eae", &
 "30042659f3226f5", &
 "48b9e4cd7d142db", &
 "728bcd4b38308fb", &
 "c0c504b031ef126", &
 "314fd3bb18bcafd", &
 "1c29148305faec1", &
 "44c92a9c28ada63", &
 "88e99b370aae32b", &
 "695081690386ad8", &
 "572d0a8de3da1ea", &
 "467f6610f357b2b", &
 "733d008563da1a3", &
 "d1baf4aacb84087", &
 "4315551d71c8ff0", &
 "48bde4cd7d140db", &
 "3ebd58f9b0da9fc", &
 "51baf4aacb84083", &
 "814e4f4de9b082c", &
 "814ecf4de9b086c", &
 "be0d1bbbb0fa0be", &
 "4f7580947c792b3", &
 "cdf2dce48c39c3b", &
 "d8c5c115f91bc12", &
 "a94e6f4debb28ee", &
 "be2d5afbb0da1be", &
 "cdd6dce48439c2b", &
 "bebd5af9b0da1fe", &
 "fa2892444a6e66b", &
 "51bbf4aacb8c083", &
 "baa73d81eebcd83", &
 "79a2ce47f138cc9", &
 "cc28cf198e6dbd4", &
 "fcde94dfcc9cc64", &
 "1016fcf59286717", &
 "12917ce2fc4dbf4", &
 "4fbc1647e9708c8", &
 "3e382b1cc974fae", &
 "d5bafdaad386087", &
 "0fef473eee60bd5", &
 "c0e504b031ee126", &
 "8bbf5b9797f6d2a", &
 "0eef071e6e60bd5", &
 "1806fcf59386517", &
 "fcdc94df8c9cc64", &
 "141eca2bfa25656", &
 "5fbc1767e9708e8", &
 "5aa4c7803a6bdf1", &
 "b14bd3b718bcafd", &
 "3ebd5af9b0da1fc", &
 "d0a7148c5b8ca09", &
 "a94ecf4debb086e", &
 "733d808563ca1a3", &
 "fd9abd1d92d0f31", &
 "bc091bbbb0fe09e", &
 "d0c514b0b0ef122", &
 "4f7d80947c7d2b3", &
 "8b3f5b97b7f6d2a", &
 "4fbc1767e9708c8", &
 "cebf4f9796f4502", &
 "9c76c880a864e67", &
 "abc1c984f95244e", &
 "795081690786ad8", &
 "467f6710f357b3b", &
 "1c380b14c9f4eae", &
 "d5baf5aac386087", &
 "bedc94df8c95c64", &
 "553d0a8de2da1fa", &
 "0315551d71d8ff0", &
 "1c1eca2ffa25656", &
 "d4bafdaad3c6087", &
 "be2d5bfbb0da0be", &
 "b0062659f3207f5", &
 "5ffc1765e9708e8", &
 "8d62e8bcd303e33", &
 "cc08cf198e69bd4", &
 "573d0a8de3da1fa", &
 "cd56dce48639c2b", &
 "472dc094546c2b2", &
 "7950a16907868d8", &
 "7283cf4b38308fb", &
 "894ecf4de9b086e", &
 "0f7580b47c792b3", &
 "cfbf4b9796f4d0a", &
 "3e380b14c974fae", &
 "732d0085e3da1a3", &
 "1816fcf59386717", &
 "532d088fe3da1ab", &
 "1c300b94c9fcaae", &
 "d0a71c8c5b8ca19", &
 "9e84bd3d5d78d09", &
 "225083508ec830a", &
 "f99abd1d12d0f31", &
 "35f4aa19cb673c0", &
 "cdd2dce48c39c2b", &
 "0f7780b47c792bf", &
 "0e33a5f114f5730", &
 "bc05b4c4ab0d850", &
 "1c300b14c9f4aae", &
 "cfbc1e47ed708e8", &
 "0f7180b47c392b3", &
 "d8c7c115f91be12", &
 "c09148adfa94e97", &
 "9c66c880a844e67", &
 "2226c13b73519f8", &
 "cebf4b9796f4d02", &
 "c0e706b031ee126", &
 "6a6629715e53ce3", &
 "73f9aa824e7d0b8", &
 "473d80947c6c2b2", &
 "1df140e0ddb5632", &
 "473dc0945c6c2b2", &
 "81b4d95f671971d", &
 "663945ca758e2b6", &
 "02ec3d98a2306fd", &
 "5dadb0fa1275690", &
 "4bb8aaa854948d0", &
 "8359ba40886971c", &
 "49cc3d2a2be2ee0", &
 "bfdf13af137f318", &
 "a1de773a2b1ff04", &
 "8ff3945a2f465c7", &
 "532d0087e3da1a3", &
 "f3eaf7fa454d385", &
 "a606aa5aeba07d9", &
 "67f0627b0af8a53", &
 "56698bed69d1c2c", &
 "d5f420011fbf924", &
 "2a8f86c810e2c62", &
 "43cc1cf1208c206", &
 "ee784c4900258de"/

data colorder/     &
0,1,2,3,4,5,6,7,8,9,10,11,123,12,13,14,15,16,17,18, &
19,20,21,22,23,24,25,138,26,145,27,28,29,30,31,32,33,34,35,36, &
37,154,38,39,40,41,42,43,44,144,46,47,48,49,50,51,52,53,143,54, &
125,56,57,58,124,59,120,140,157,160,55,60,61,62,156,162,141,64,65,153, &
181,183,66,170,67,68,69,130,70,164,71,72,73,74,75,63,76,77,135,78, &
79,80,176,169,82,83,84,167,180,85,136,158,129,166,175,142,134,146,121,165, &
88,89,192,90,45,91,92,93,182,189,94,95,96,173,81,97,98,178,122,126, &
132,99,100,152,186,193,101,102,151,103,104,172,159,168,150,190,147,148,201,107, &
205,177,108,198,197,174,127,109,185,110,202,87,199,171,179,187,139,137,106,131, &
206,194,112,149,155,113,128,184,196,86,114,203,212,195,208,105,188,161,163,191, &
200,209,214,204,115,218,133,111,207,117,213,216,211,217,116,215,219,220,210,221, &
118,222,223,225,224,228,226,229,231,227,233,119,234,235,232,230,237,239,236,238, &
240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255,256,257,258,259, &
260,261,262,263,264,265,266,267,268,269,270,271,272,273,274,275,276,277,278,279, &
280,281,282,283,284,285,286,287,288,289,290,291,292,293,294,295,296,297,298,299/

save first,gen

if( first ) then ! fill the generator matrix
  gen=0
  do i=1,240
    do j=1,15
      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, 240
  nsum=0
  do j=1, 60 
    nsum=nsum+message(j)*gen(i,j)
  enddo
  pchecks(i)=mod(nsum,2)
enddo
itmp(1:240)=pchecks
itmp(241:300)=message(1:60)
codeword(colorder+1)=itmp(1:300)

return
end subroutine encode300