In this work we consider incremental redundancy (IR) hybrid automatic repeat request (HARQ), where transmission rounds are carried out over independent block-fading channels. We propose the so-called multi-packet HARQ where the transmitter allows different packets to share the same channel block. In this way the resources (block) are optimally assigned throughout the transmission rounds. This s...

In this paper, we propose a new coding scheme for the general relay channel. This coding scheme is in the form of a block Markov code. The transmitter uses a superposition Markov code. The relay compresses the received signal and maps the compressed version of the received signal into a codeword conditioned on the codeword of the previous block. The receiver performs joint decoding after it has...

For a fading Gaussian multiple access channel with user cooperation, we obtain the optimal power allocation policies that maximize the rates achievable by block Markov superposition coding. The optimal policies result in a coding scheme that is simpler than the one for a general multiple access channel with generalized feedback. This simpler coding scheme also leads to the possibility of formul...

For a fading Gaussian multiple access channel with user cooperation, we obtain the optimal power allocation policies that maximize the rates achievable by block Markov superposition coding. The optimal policies result in a coding scheme that is simpler than the one for a general multiple access channel with generalized feedback. This simpler coding scheme also leads to the possibility of formul...

Conventional block-based image classiication algorithms, such as CART and VQ based clas-siication, ignore the statistical dependency among image blocks. Consequently, these algorithms often suuer from over-localization. In order to beneet from the inter-block dependency, an image classiication algorithm based on a hidden Markov model (HMM) is developed. An HMM for image classiication, a two dim...

The Lapped Orthogonal Transform (LOT) [1][3] is a new transform for block image coding. It has basis functions that overlap adjacent blocks and decay smoothly to zero, and so it can reduce the blocking effect to very low levels, without any data overhead. In t'his paper we show that a quasi-optimal LOT can be computed with an algorithm based on the discrete cosine transform (DCT), with only 30 ...

The detection of community structure in networks is intimately related to finding a concise description of the network in terms of its modules. This notion has been recently exploited by the map equation formalism [Rosvall and Bergstrom, Proc. Natl. Acad. Sci. USA 105, 1118 (2008)] through an information-theoretic description of the process of coding inter- and intracommunity transitions of a r...

A distortion-computation function D(C) is de ned as the minimum expected distortion in computing some quantity while using no more than C computational units. In a communication framework, where the computational problem is to determine a representation that can be transmitted with expected rate not exceeding R, this gives slices of a rate-distortion-computation surface. The convexity of distor...

This work is devoted to practical joint source channel coding. Although the proposed approach has more general scope, for the sake of clarity we focus on a specific application example, namely, the transmission of digital images over noisy binary-input output-symmetric channels. The basic building blocks of most stateof the art source coders are: 1) a linear transformation; 2) scalar quantizati...