Patent ID: 8745460

Claim:
An encoder comprising: an input interface configured to receive a data stream; a processor configured to map the received data stream into corresponding codewords; and an output interface configured to output said codewords, wherein said processor is configured to map packets of the received data stream, each packet comprising a sequence of packet symbols, into respective codewords, each codeword comprising a sequence of codeword symbols, using an encoding scheme corresponding to a parity check matrix that is derived from a bipartite protograph, wherein the bipartite protograph comprises: a plurality of groups of nodes, each group of nodes comprising variable nodes and a first plurality of check nodes, each variable node corresponding to a codeword symbol position, wherein each of the check nodes in the first plurality of check nodes is of degree two and is connected to two variable nodes in the same group and wherein each of the groups of nodes forms a parallel path in the bipartite protograph, wherein each variable node in the bipartite protograph belongs to one of the groups of nodes; and a second plurality of check nodes of degree n, n being the number of said plurality of groups, wherein each of the second plurality of check nodes is connected to a variable node in each group such that the codeword symbol positions in each codeword are interleaved between the groups of nodes.