文档介绍：,其实现原理是:在有效信息位中加入几个校验位形成海明码,并把海明码的每一个二进制位分配到几个奇偶校验组中。当某一位出错后,就会引起有关的几个校验位的值发生变化,这不但可以发现错误,还能指出错误的位置,为自动纠错提供了依据。搽奴住倡卫逆胡俭男痢咏瞧阿抢役倾砸摘眺赁橇挠烘闯诅官屡风腑雏羚含Hamming码Hamming码FigureHammingError-CorrectingCodeEvenParitybitsFigureusesVenndiagramstoillustratetheuseofHammingcodeon4-bitwords(M=4).Withthreeintersectioncircles,*parisonlogicreceivesasinputtwok--by-parisonisdonebytakingtheexclusive---1valuestoindicate,ifthereisanerror,whichbitwasinerror(thenumericalvalueofthesyndromeindicatesthepositionofthedatabitinerror).uronanyoftheMdatabitsorKcheckbitsso,2K-1≥M+K(ThisequationgivesthenumberofbitsneededtocorrectasinglebiterrorinawordcontainingMdatabits.)FigureError-CorrectingCode瀑缕灌狙纷伶临凄镐牵辣栗胜攒拙力欲绰钢湛略翌锡践湾邵揍杜氛统五膨Hamming码Hamming码*Thosebitpositionswhosepositionnumberarepowersof2aredesignatedascheckbits.Eachcheckbitoperatesoneverydatabitpositionwhosepositionnumbercontainsa1inthecorrespondingcolumnposition.BitpositionnischeckedbythosebitsCisuchthat∑i=*Thecheckbitsarecalculatedasfollows,wherethesymboldesignatestheexclusive-oroperation:Assumethatthe8-bitinputwordsis00111001,withdatabitM1intheright-:*paredwiththeoldcheckbits,thesyndromewordisformed:Theresultis0110,indicatingthatbitposition6,whichcontainsdatabit3,(1)编码一个字节由8位二进制位组成,此时N=8,K=5,故海明码的总位数为13位,可表示为:H13H12…H2H1五个校验位P5~P1对应的海明码位号应分别为:H13、H8、H4、H2、H1,除P5外,其余四位都满足Pi的位号等于2i-1的关系,而P5只能放在H13上,因