Rate-compatible punctured ldpc codes with two subgraphs

Gou Hosoya, Hideki Yagi, Manabu Kobayashi

Gou Hosoya

Badri N. Vellambi, R. Badri, Faramarz Fekri

In this paper, we study rate-compatible puncturing of finite-length Low-Density Parity-Check (LDPC) codes. First, we derive simple and yet good bounds on the expected performance of punctured codes (constructed by random puncturing) over Binary Erasure Channel (BEC) as a function of the performance of their parent LDPC code. We then present a novel rate-compatible puncturing scheme that is very easy to implement. Our scheme uses the idea that a more uniform distribution of punctured bits across the Tanner graph results in punctured codes with better performance. Although the puncturing scheme tailored to regular codes is presented, it is also directly applicable to irregular parent ensembles. By simulations, the proposed rate-compatible puncturing scheme is shown to be superior to the existing puncturing methods for both regular and irregular LDPC codes over BEC and Additive White Gaussian Noise (AWGN) Channel.

Bing Zhang, He-Guang Su, Shu‐Tao Xia

Finding good puncturing patterns for rate compatible non-binary LDPC codes are considered over additive white Gaussian noise (AWGN) channels in this paper. We first study several popular puncturing schemes for binary LDPC codes and generalize them to non-binary LDPC codes, where the effects of short cycles in Tanner graph are rarely investigated. By care fully studying the impacts of short cycles when puncturing, we put forward a novel puncturing scheme for rate-compatible non binary LDPC codes. Simulation results show that the proposed puncturing scheme is superior to the above known ones for rate compatible non-binary LDPC codes over AWGN channels at certain cases.

S. Babvey, Stephen McLaughlin

Gou Hosoya, Hideki Yagi, Manabu Kobayashi

An iterative decoding algorithm of rate-compatible punctured low-density parity-check (RCP-LDPC) codes of high coding rates is developed. This algorithm performs a predetermined recovering process of punctured bits sums at the beginning of each iteration of the standard belief-propagation (BP) decoding algorithm. By propagating messages of two punctured bits sum, this algorithm can recover much more punctured bits than the standard BP decoding algorithm. It is shown that the proposed algorithm is applicable for RCP-LDPC codes of higher coding rates with little increase of decoding complexity.