Early Detection Algorithm for Decoding LDPC Codes

Ho-Il Kim, 김호일

Ji-Won Jung

In this paper, we first review LDPC codes in general and a belief propagation algorithm that works in logarithm domain. LDPC codes, which is chosen for second generation digital video broadcasting standard, are required a large number of computation due to large size of coded block and iteration. Therefore, we presented two kinds of low computational algorithm for LDPC codes. First, sequential decoding with partial group is proposed. It has same H/W complexity, and fewer number of iteration's are required at same performance in comparison with conventional decoder algerian. Secondly, early detection method for reducing the computational complexity is proposed. Using a confidence criterion, some bit nodes and check node edges are detected early on during decoding. Through the simulation, we knew that the iteration number are reduced by half using subset algorithm and computational complexity of early detected method is about offs in case of check node update, offs in case of check node update compared to conventional scheme.

Vikram Arkalgud Chandrasetty, Syed Mahfuzul Aziz

Ligter, Luca

Cheng-Hung Lin, M.-K. Ku

A fast, successful decoding detection mechanism is proposed for dual-diagonal block-based low-density parity-check (LDPC) codes. The algorithm eliminates unnecessary parity check computation by exploiting the structure of dual-diagonal LDPC codes. The average number of decoding iterations can be reduced for both two-phase decoders and layered decoders with no performance degradation on the AWGN channel. Simulation results show that the proposed mechanism reduces average iterations by 10–15% at 10−5 bit error rate compared with standard parity-check equations.

Tom Høholdt, JØrn Justesen