Method and apparatus for encoding long and short block length low density parity check (LDPC) codes

摘要

An approach is provided for generating Low Density Parity Check (LDPC) codes. The approach provides efficient encoding based on a special structured parity check matrix. An LDPC encoder (203) generates an LDPC code with an outer Bose Chaudhuri Hocquenghem (BCH) code. For 1/3 rate, the relevant parameters are as follows: q = 120, nldpc = 64,800, kldpc = nBCH = 21600, kBCH = 21408 (12 bit error correcting BCH). For 1/ 4 rate, the LDPC code has the following relevant parameters: q = 135, nldpc = 64,800, kldpc = nBCH = 16200, kBCH = 16008 (12 bit error correcting BCH). For 2/5 rate, the following parameters exist: q = 108, nldpc = 64800, kldpc = nBCH = 25920, kBCH = 25728 (12 bit error correcting BCH). The above approach has particular application in digital video broadcast services over satellite.