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This thesis addresses the topic of Low-Density Parity-Check (LDPC) code analysis, both asymptotically and for finite block lengths. Since in general it is a difficult problem to analyze individual code instances, ensemble averages are studied by following ...
We give a short survey of several techniques to construct codes on GF(q) that approach the capacity of the q-ary symmetric channel. The q-ary symmetric channel represents the next level of difficulty after the binary erasure channel (BEC). Since the channe ...
Transmission of packets over computer networks is subject to packet-level errors, which appear as "bursts" of bit-level errors and are not well modeled by memoryless binary channels. A standard scrambling technique is used for transmission of packets by th ...
In this paper we investigate the behaviour of iteratively decoded low-density parity-check codes over the binary erasure channel in the so-called "waterfall region". We show that, according to a simplified model, the performance curves in this region follo ...
In this article we present an efficient approach for the implementation of optimum maximum likelihood decoding of QPSK modulated multiple-input-multiple-output data streams. The proposed method does not compromise optimality of the detection algorithm. Ins ...
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Communication over unknown binary symmetric channels with instantaneous and perfect feedback is considered. We describe a universal scheme based on a decision feedback strategy. ...
Communication over unknown binary symmetric channels with instantaneous and perfect feedback is considered. We describe a universal scheme based on a decision feedback strategy. ...
We prove that for any given R between 0 and 1 the best threshold value for a regular LDPC code of rate R with common variable degree v and common check degree c occurs when v is at least 3 and is minimal subject to the condition R=1−v/c ...
This paper extends the construction and analysis of Raptor codes originally designed in A. Shokrollahi (2004) for the erasure channel to general symmetric channels. We explicitly calculate the asymptotic fraction of output nodes of degree one and two for c ...
We investigate the average erasure probability of the belief propagation algorithm over the binary erasure channel (BEC) for various finite-length low- density parity-check (LDPC) ensembles. In particular, we give tight upper bounds on the "error floor", i ...