LDPC DESIGN USING QUASI CYCLIC CONSTRUCTIONS AND PUNCTURING FOR HIGH RATE HIGH PARALLELISM AND LOW ERROR FLOOR

摘要

A method of LDPC encoding/decoding is disclosed. An encoder receives a set of information bits and performs a lifted LDPC encoding operation on the information bits to produce a codeword using a base LDPC code including one or more punctured nodes. The base LDPC code including the one or more punctured nodes has no multiple edges between node pairs whereas the base LDPC code without the one or more punctured nodes has multiple edges between node pairs. Thus a punctured node is used to eliminate multiple edges in the base graph for the lifted LDPC code. The encoder then punctures all lifted bits of the codeword that correspond to the one or more punctured base bits of the base LDPC code. The one or more punctured base bits are those that correspond with one or more punctured base nodes respectively of the base LDPC code. For some embodiments the one or more punctured base nodes correspond to one or more degree 2 variable nodes. The LDPC decoder treats the punctured codeword bits as erased during the iterative decoding operation.