Investigations on Binary and Non-Binary LDPC Codes

Kasai Kenta

Sekson Timakul, Somsak Choomchuay

In LDPC code, the structure of code's parity check matrix plays the crucial role in code performance. In this paper proposes the preliminary investigation of a designed parity check matrix from Tanner. We modify this technique in to non binary LDPC structure and decoding with FFT-SPA. We take into high code rate application more than 0.8. The result has shown that in bit error rate (BER) compare between non-binary LDPC and binary LDPC. In our results, the performance of non binary LDPC has better than binary LDPC.

Zhongxun Wang, Juan Hui

This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity index Low Density Parity Check Code（LDPC） is a kind of linear block codes based on sparse check matrix. As a kind of channel coding, whose error performance approach Shannon limits, it has better error correction capability, more flexible structure and lower decoding complexity. Currently most of the LDPC code researches are on the premise of the AWGN channel and BSC channel, which mainly in the range of the binary LDPC codes. According to the above problem, this paper analyzes the various decoding performance of non-binary LDPC codes in Rayleigh channel, and realizes a non-binary LDPC decoder in Rayleigh channel through the FPGA design. The paper begins with an overall discussion of issues surrounding the use of non-binary LDPC codes. And then the bit-error-rate (BER) performances of different non-binary LDPC codes decoding algorithm are compared on the independent Rayleigh fading channel. Finally, this decoder design is implemented based on 5CSEMA5F31C6 FPGA (devised by Altera Company) to illustrate the concepts discussed in the paper.

健太 笠井, Kenta Kasai

Kenta Kasai, Kohichi Sakaniwa

Vishwambhar Rathi

We consider transmission over the binary erasure channel (BEC) using non-binary LDPC codes. We generalize the concept of stopping sets to non-binary LDPC codes. We give a combinatorial characterization of decoding failures for non-binary LDPC codes decoded via Belief Propagation (BP). Using the density evolution analysis, we compute the asymptotic residual degree distribution for non-binary LDPC codes. In order to show that asymptotically almost every code in the non-binary LDPC ensemble has a rate equal to the design rate, we generalize the arguments of Measson, Montanari, and Urbanke to the non-binary setting. This generalization enables us to compute the conditional entropy of non-binary LDPC codes. We observe that the Maxwell construction of Measson, Montanari, and Urbanke relating the performance of MAP and BP decoding, holds in the setting of non-binary LDPC codes.