function?vHat?=?decodeBitFlipping（rx?H?iteration）
%?Hard-decision/bit?flipping?sum?product?algorithm?LDPC?decoder
%
%??rx????????:?Received?signal?vector?（column?vector）
%??H?????????:?LDPC?matrix
%??iteration?:?Number?of?iteration
%
%??vHat??????:?Decoded?vector?（0/1）?
%
%
%?Copyright?Bagawan?S.?Nugroho?2007?
%?http://bsnugroho.googlepages.com

[M?N]?=?size（H）;

%?Prior?hard-decision
ci?=?0.5*（sign（rx‘）?+?1）;

%?Initialization
rji?=?zeros（M?N）;

%?Asscociate?the?ci?matrix?with?non-zero?elements?of?H
qij?=?H.*repmat（ci?M?1）;
?
%?Iteration
for?n?=?1:iteration
???
???fprintf（‘Iteration?:?%d\n‘?n）;
???
???%?-----?Horizontal?step?-----
???for?i?=?1:M
??????
??????%?Find?non-zeros?in?the?column
??????c1?=?find（H（i?:））;
??????
??????%?Get?the?summation?of?qij\c1（k）????????
??????for?k?=?1:length（c1）

?????????rji（i?c1（k））?=?mod（sum（qij（i?c1））?+?qij（i?c1（k））?2）;
?????????
??????end?%?for?k
??????
???end?%?for?i
???
???%?------?Vertical?step?------
???for?j?=?1:N

??????%?Find?non-zero?in?the?row
??????r1?=?find（H（:?j））;
??????
??????%?Number?of?1s?in?a?row
??????numOfOnes?=?length（find（rji（r1?j）））;
??????
??????for?k?=?1:length（r1）????????

?????????%?Update?qij?set?‘1‘?for?majority?of?1s?else?‘0‘?excluding?r1（k）
?????????if?numOfOnes?+?ci（j）?>=?length（r1）?-?numOfOnes?+?rji（r1（k）?j）
????????????qij（r1（k）?j）?=?1;
?????????else
????????????qij（r1（k）?j）?=?0;
?????????end
??????????
??????end?%?for?k
??????
??????%?Bit?decoding
??????if?numOfOnes?+?ci（j）?>=?length（r1）?-?numOfOnes
?????????vHat（j）?=?1;
??????else
?????????vHat（j）?=?0;
??????end
?????????????
???end?%?for?j
???
end?%?for?n

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1697??2007-05-04?19:06??decodeBitFlip.m
?????文件????????2568??2007-05-04?19:09??decodeLogDomain.m
?????文件????????2169??2007-05-04?19:06??decodeLogDomainSimple.m
?????文件????????2468??2007-05-04?19:06??decodeProbDomain.m
?????文件????????2009??2007-05-04?19:31??ldpcBER.m
?????文件????????1541??2010-02-25?10:25??license.txt
?????文件????????3468??2007-05-04?19:15??makeLdpc.m
?????文件????????3819??2007-05-04?18:25??makeParityChk.m