公开(公告)号：EP1841073A1

公开(公告)日：2007-10-03

申请号：EP06006521.6

申请日：2006-03-29

Applicant: STMicroelectronics N.V.

Inventor： Kienle, Franck ,  Wehn, Norbert ,  Brack, Torben

IPC: H03M13/11

CPC classification number: H03M13/3905 ,  H03M13/1165 ,  H03M13/1197 ,  H03M13/3972

Abstract: Method of decoding LDPC codes such as IRA codes used in the DVB-S2 standard, the code graph comprising first variable nodes (systematic), second variable nodes (parity) having a degree two, and check nodes connected to second variable nodes by a zigzag connectivity, the method comprising
a) grouping the check nodes into at least one group, the check nodes of each group being connected by variable nodes called internal variable nodes,
b) performing for each group (GR i ) the following sub-steps b1) and b2):
b1) jointly updating (71) all the check nodes of said group by using an algorithm of the Maximum-A-Posteriori (MAP) type on a two-state trellis,
b2) updating (72,73) all the first variable nodes and all the second variable nodes (PN i-1,i ; PN i,i+1 ) connected to said group except said at least one internal second variable node,
c) iteratively repeating step b)
When using a plurality of groups, a corresponding plurality of trellis windows are LogMAP decoded without training period since connecting parity nodes are updated according the sum-product algorithm.

Abstract translation: 对DVB-S2标准中使用的诸如IRA代码的LDPC码进行解码的方法，包括具有度2的第一可变节点（系统），第二可变节点（奇偶校验）的代码图，以及通过Z字形连接到第二可变节点的校验节点 所述方法包括：a）将所述校验节点分组为至少一个组，每组的校验节点由称为内部变量节点的变量节点连接，b）对于每个组（GR i）执行以下子步骤b1） 和b2）：b1）通过使用两状态网格上的最大后验（MAP）类型的算法来共同更新（71）所述组的所有校验节点，b2）更新（72,73）所有 连接到除所述至少一个内部第二可变节点之外的所述组的第一可变节点和所有第二可变节点（PN i-1，i; PN i，i + 1），c）迭代地重复步骤b）当使用多个 组，相应的多个网格窗口是LogMAP解码而没有训练周期 根据sum-product算法更新连接奇偶校验节点。