We first consider the design of generalized LPDC (G-LDPC) codes with recursive systematic convolutional (RSC) constraint nodes in place of the standard single parity-check constraint nodes. Because rate-1/2 RSC nodes lead to low-rate G-LDPC codes, we consider high-rate tail-biting RSC nodes for which Riedel’s APP-decoder based on the reciprocal-dual code trellis becomes necessary. We then consi...

AhtractOrthogonal Frequency Division Multiplexing (OFDM) is a very attractive technique for high-hit-rate data transmission in multipath environments. Many error-correcting codes have been applied to OFDM, convolutional codes, Reed-Solomon codes, Turbo codes, and so on. Recently, low-density parity-check (LDPC) codes have attracted much attention particularly in the tield of coding theory. LDPC...

Selection combining (SC) and maximal ratio combining (MRC) with Low Density Parity-check (LDPC) enhance the performance of overall system by providing coding gain. Using Gaussian approximation (GA) approach the bit error rate of LDPC-SC, LDPC-MRC system is derived for BPSK modulation over an independent and identically distributed (i.i.d) Rayleigh fading channel. The analysis is done for the ca...

A new algorithm to construct good low-density parity-check (LDPC) codes with large stopping sets is presented. Since the minimum stopping set characterizes an LDPC code, searching for stopping sets in LDPC codes is an important issue. Large minimum stopping sets avoid the LDPC code to get trapped in cycles specially on the binary erasure channel. Dealing with stopping sets is not an easy task s...

We investigate the application of low-density parity-check (LDPC) codes in volume holographic memory (VHM) systems. We show that a carefully designed irregular LDPC code has a very good performance in VHM systems. We optimize high-rate LDPC codes for the nonuniform error pattern in holographic memories to reduce the bit error rate extensively. The prior knowledge of noise distribution is used f...

‎s‎. ‎kim et al‎. ‎have been analyzed the girth of some algebraically‎ ‎structured quasi-cyclic (qc) low-density parity-check (ldpc)‎ ‎codes‎, ‎i.e‎. ‎tanner $(3,5)$ of length $5p$‎, ‎where $p$ is a prime of‎ ‎the form $15m+1$‎. ‎in this paper‎, ‎by extension this method to‎ ‎tanner $(3,7)$ codes of length $7p$‎, ‎where $p$ is a prime of the‎ ‎form $21m‎+ ‎1$‎, ‎the girth values of tanner $(3,7...

A constant challenge in Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) codes lies on flexible code lengths and rates, conditioned by good error performance. This paper presents an optimal construction method of QC-LDPC Codes on the basis of graphical model and search algorithm. Utilizing the proposed scheme, we can construct adaptable QC-LDPC codes whose girths are no less than 12, and column ...

Hamming code-based LDPC (H-LDPC) block codes are obtained by replacing the single parity-check constituent codes in Gallager’s LDPC codes with Hamming codes. This paper investigates the asymptotic performance of ensembles of random H-LDPC codes, used over the binary symmetric channel and decoded with a low-complexity hard-decision iterative decoding algorithm. It is shown that there exist H-LDP...