Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.
AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.
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 ...
It is well known and surprising that the uncoded transmission of an independent and identically distributed Gaussian source across an additive white Gaussian noise channel is optimal: No amount of sophistication in the coding strategy can ever perform bett ...
The paper gives an information theoretic analysis of the potential of chaos in digital communication schemes, underlining that there is no fundamental principle that speaks against the use of chaotic systems in digital communications. The channel model con ...
The paper describes the state of the art in the design of receivers for chaos based digital communication over noisy channels. In the first part, an information theoretic analysis of the potential of chaos in digital communication schemes is given, underli ...
This paper starts a systematic study of capacity-achieving (c.a.) sequences of low-density parity-check codes for the erasure channel. We introduce a class A of analytic functions and develop a procedure to obtain degree distributions for the codes. We sho ...
In this paper we will survey some of the most recent results on low-density parity-check codes. Our emphasis will be primarily on the asymptotic theory of these codes. For the most part, we will introduce the main concepts for the easier case of the erasur ...
In this work, two algorithms for closed loop power control in CDMA wireless systems are proposed. These algorithms aim to minimize the power control error by predicting the inverse of the channel fading: For this purpose, a channel fading prediction scheme ...
This paper studies the tracking performance of adaptive filters operating in the presence of two sources of nonstationarities: carrier frequency offsets and random channel variations. Both impairments are common in digital communications due to mismatches ...
This paper addresses the problem of soft equalization for space-time-coded transmissions over frequency-selective fading channels. The structure of the space-time code is embedded in the channel impulse response for efficient joint equalization and decodin ...
We determine the capacity of a particular large Gaussian relay network in the limit as the number of relays tends to infinity. The upper bounds follow from a cut-set argument, and the lower bound follows from an argument involving uncoded transmission. We ...
