We present a symmetric LDPC code with constant rate and constant distance (i.e. good LDPC code) that its constraint space is generated by the orbit of one constant weight constraint under a group action. Our construction provides the first symmetric LDPC good codes. This solves the main open problem raised by Kaufman and Wigderson in [4].

This paper considers the optimization of multi-edge type low-density parity-check (METLDPC) codes to maximize the decoding threshold. We propose an algorithm to jointly optimize the node degree distribution and the multi-edge structure of MET-LDPC codes for given values of the maximum number of edge-types and maximum node degrees. This joint optimization is particularly important for MET-LDPC c...

In this paper, we investigate the joint design of channel and network coding in bidirectional relaying systems and propose a combined low complexity physical network coding and LDPC decoding scheme. For the same LDPC codes employed at both source nodes, we show that the relay can decode the network coded codewords from the superimposed signal received from the BPSK-modulated multiple-access cha...

A low-density parity-check (LDPC) code is a linear error correcting code, and is used for transmitting message over a noisy transmission channel. A new class of error correcting codes called EG-LDPC (Euclidean Geometry-LDPC) codes and its encoder and decoder architectures for nanomemory applications is designed. EG-LDPC codes also have fault secure detection capability. One step majority logic ...

This paper presents the H-ARQ techniques comparison for OFDM systems with a new family of non-binary LDPC codes which has been developed within the EU FP7 DAVINCI project. The punctured NB-LDPC codes have been used in a simulated model of the transmission system. The link level performance has been evaluated in terms of spectral efficiency, codeword error rate and average number of retransmissi...

In this paper, a serial concatenation scheme and its iterative decoding algorithm between Low Density Parity Check codes (LDPC) and Reed-Solomon codes are proposed. For the decoder, the soft output values delivered by LDPC are used as reliability values to perform the Chase decoding of Reed-Solomon (RS) codes which return soft information to LDPC decoder. This approach presents an option scheme...

We introduce multi-edge type LDPC codes, a generalization of the concept of irregular LDPC codes that yields improvements in performance, range of applications, adaptability and error floor. The multiedge type LDPC codes formalism includes various constructions that have been proposed in the literature including, among others, concatenated tree (CT) codes [1], (generalized irregular) repeat acc...

42 JANUARY 2004 1053-5888/04/$20.00©2004IEEE e consider the problem of designing unoriented bipartite graphs with large girth. These graphs are the Tanner graphs associated with the parity-check matrix H of low density parity-check (LDPC) codes or Gallager codes. Larger girth improves the computational and bit error rate (BER) performance of these codes. The article overviews several existing m...