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Two incremental redundancy hybrid ARQ (IR-HARQ) schemes are proposed, analyzed, and compared: one is based on LDPC code ensembles with random transmission assignments, the other is based on recently introduced Raptor codes. A number of important issues, such as rate and power control, Raptor code design, and error rate performance after each transmission on(More)
—We propose an augmented belief propagation (BP) decoder for low-density parity check (LDPC) codes which can be utilized on memoryless or intersymbol interference channels. The proposed method is a heuristic algorithm that eliminates a large number of pseudocodewords that can cause nonconvergence in the BP decoder. The augmented decoder is a multistage(More)
Two incremental redundancy hybrid ARQ (IR-HARQ) schemes are compared: one is based on LDPC code ensembles with random transmission assignments, the other is based on recently introduced Raptor codes. A number of important issues, such as rate and power control, and error rate performance after each transmission on time varying binary-input, symmetric-output(More)
In this paper, we design capacity-approaching codes for partial response channels. The codes are constructed as concatenations of inner trellis codes and outer low-density parity- check (LDPC) codes. Unlike previous constructions of trellis codes for partial response channels, we disregard any algebraic properties (e.g., the minimum distance or the(More)
— We propose a coding/decoding strategy to approach the channel capacities for binary intersymbol interference (ISI) channels. The proposed codes are serially concatenated codes: inner matched information rate codes and outer irregular low-density parity-check (LDPC) codes. The whole system is iteratively decodable. Binary ISI channel models are appropriate(More)
An LDPC code based hybrid ARQ scheme with random transmission assignments is analyzed. The spectrum properties of LDPC code ensembles that are necessary for this analysis are derived. Very good estimates of maximum-likelihood decoding error rates after each transmission are provided. The results are tested on practical code examples by simulation
— In recent years performance prediction for communication systems utilizing iteratively decodable codes has been of considerable interest. There have been significant breakthroughs as far as the analysis of LDPC code ensembles is concerned but the more practical problem of predicting the FER/BER of a particular code has proved to be much more difficult. In(More)