The subject of this paper is the design of lowdensity parity-check (LDPC) codes concatenated with a Gray mapped quaternary phase shift keying (QPSK) modulator for transmission over inter-symbol (ISI) channels. In particular, we will present several results considering important partial response channels (PRCs). Using an extrinsic information transfer (EXIT) chart-based analysis, we give insight...

This paper develop a low complexity composite CDMA system based on MIMO (Multiple-Input-Multiple-Output) processing and LDPC(low-density parity-check) codec based CDMA systems, involved the complicated case of multipath, multiusers and short length LDPC codes. To explore the practical application, the mobile user in the composite CDMA systems is with only two antennas and adopts short length ir...

In this paper, we discuss a construction of CSS codes derived from pairs of practical irregular LDPC codes. Intersection studies between quantum error-correcting codes and LDPC codes are current hot research topics [1], [3], [4], [5], [6], [7], [8], [9]. One of aims of quantum error-correcting code theory is to construct quantum error-correcting codes with small length and high error-correcting...

A three terminal relay system with binary erasure channel (BEC) was considered, in which a source forwarded information to a destination with a relay’s ”assistance”. The nested LDGM (Low-density generator-matrix) -LDPC (lowdensity parity-check) was designed to realize Compress-andforward (CF) at the relay. LDGM coding compressed the received signals losslessly and LDPC realized the binning for ...

The performance of low-density parity-check (LDPC) codes serially concatenated with generalized partial response channels is investigated. Various soft-input/soft-output detection schemes suitable for use in iterative detection/decoding systems are described. A low-complexity near-optimal detection algorithm that incorporates soft-input reliability information and generates soft-output reliabil...

31 Abstract—This paper investigates on the low density parity-check (LDPC) decoding algorithms and the detection methods of the multiple-input multiple-output (MIMO) systems. For LDPC codes, min-sum and layered decoding algorithms are discussed, and for MIMO detection, the maximum likelihood (ML) decision based on the sphere decoding algorithm is mainly analyzed. Also, the performance of the co...

Trapping sets are considered the primary factor for degrading the performance of low-density parity-check (LDPC) codes in the error-floor region. The effect of trapping sets on the performance of an LDPC code becomes worse as the code size decreases. One approach to tackle this problem is to minimize trapping sets during LDPC code design. However, while trapping sets can be reduced, their compl...

Low-density parity-check (LDPC) codes have been shown to deliver capacity approaching performance; however, problematic graphical structures (e.g. trapping sets) in the Tanner graph of some LDPC codes can cause high error floors in bit-errorratio (BER) performance under conventional sum-product algorithm (SPA). This paper presents a serial concatenation scheme to avoid the trapping sets and to ...

The use of low-density-parity-check (LDPC) codes in coding digital messages has aroused much research interest because of their excellent bit-error performance. The behavior of the iterative LDPC decoders of finite length, however, has not been fully evaluated under different signal-tonoise conditions. By considering the finite-length LDPC decoders as high-dimensional nonlinear dynamical system...

For high density magnetic recording channels and memory systems, low-density parity-check (LDPC) codes with probabilistic decoding are replacing Reed-Solomon (RS) codes or Bose-Chaudhuri-Hocquenghem (BCH) codes with conventional algebraic decoding. The main benefit of LDPC codes over the RS and BCH codes is that LDPC codes can provide lower error probabilities than equivalent conventional codes...