For The Enhancement of BER In Communication System We Use The Different Type of Channel coding. LDPC(low density parity check) are the codes Which are used in channel coding for the different enhancement in the system performance. We are trying LDPC channel coding with BPSK modulation scheme with MRC and EGC at the receiver over Rayleigh fading channel. BER Performance of System is analyzed wit...

Low-density parity-check (LDPC) codes can be constructed using constituent block codes other than single parity-check (SPC) codes. This paper considers random LDPC codes with constituent Hamming codes and investigates their asymptotic performance over the binary erasure channel. It is shown that there exist Hamming code-based LDPC codes which, when decoded with a low-complexity iterative algori...

We propose a new decoding algorithm of LDPC codes over the binary erasure channel (BEC). The proposed decoding algorithm is an iterative one which uses the sparseness structure of the parity-check matrix of LDPC codes. We show by simulation results that the proposed decoding algorithm and the conventional decoding algorithm have a trade-off between remaining erasure rate and complexity. Keyword...

In this correspondence, low-density parity-check (LDPC) codes are applied to lossy source coding and we study how the asymptotic performance of MacKay’s LDPC codes depends on the sparsity of the parity-check matrices in the source coding of the binary independent and identically distributed (i.i.d.) source with Pr = 1 = 0 5. In the sequel, it is shown that an LDPC code with column weight (log )...

We consider the use of wideband systems for the fixed pointto-point transmission of coded data with low hit-error rate requirements. A system is defined which is based (in OFDM transmission with PSK and QAM subcarrier modulation, error control coding using low-density parity-check (LDPC) codes, and channel equalization to reduce intersymbol interference from a fading channel. Tradeoffs between ...

This paper presents a construction of low-density parity-check (LDPC) codes based on the incidence matrices of oval designs. The new LDPC codes have regular parity-check matrices and Tanner graphs free of 4-cycles. Like the finite geometry codes, the codes from oval designs have parity-check matrices with a large proportion of linearly dependent rows and can achieve significantly better minimum...

SUMMARY Low-density parity-check (LDPC) codes are shown to tightly approach the performance of idealized maximum distance separable (MDS) codes over memoryless erasure channels, under maximum likelihood (ML) decoding. This is possible down to low error rates and even for small and moderate block sizes. The decoding complexity of ML decoding is kept low thanks to a class of decoding algorithms, ...

In this paper we construct a class of regular Low Density Parity Check (LDPC) codes derived from Latin squares. The parity check matrices of these codes are constructed by permuting shift-orthogonal Latin squares of order n in blockrows and block-columns. I show that the constructed LDPC codes are self-orthogonal and their minimum and stopping distances are bounded. This helps us to construct a...

Product accumulate codes are a special case of differentially coded low density parity check (LDPC) codes. This work analyzes the noncoherent performance of PA codes and general differentially-coded LDPC codes on flat Rayleigh fading channels using extrinsic information transfer charts, and proposes a convergence-constraint method to design good LDPC ensembles matched to differential coding.

This letter investigates the combination of the Chase-2 and sum-product (SP) algorithms for low-density parity-check (LDPC) codes. A simple modification of the tanh rule for check node update is given, which incorporates test error patterns (TEPs) used in the Chase algorithm into SP decoding of LDPC codes. Moreover, a simple yet effective approach is proposed to construct TEPs for dealing with ...