Patent ID: 8190981
Filing Date: 2012-05-29
Classification: H03M,H04L

Abstract:
1. A transmitter in a communication system, comprising: an interleaver for interleaving Low Density Parity Check (LDPC) codeword bits included in an LDPC codeword using an interleaving scheme and outputting the interleaved LDPC codeword bits by a size of a modulation symbol being generated using a modulation scheme, wherein the modulation symbol having a difference in reliability characteristics between modulation symbol-constituting bits included in the modulation symbol, and the LDPC codeword bits are sequentially ordered beginning from a higher-degree; and a bit mapper for mapping the interleaved LDPC codeword bits using a mapping scheme to the modulation symbol-constituting bits, wherein the mapping scheme takes into account degrees of the interleaved LDPC codeword bits, the degrees being degrees of variable nodes which are mapped one-to-one to the interleaved LDPC codeword bits, and reliability characteristics of the modulation symbol-constituting bits, and wherein the mapping scheme maps the two highest-degree bits among the interleaved LDPC codeword bits to the two lowest-reliability bits among the modulation symbol-constituting bits in an iterative manner.