Publications de Soheil Mohajerzefreh

Graph-Constrained Group Testing

Amin Karbasi, Mahdi Cheraghchi Bashi Astaneh, Soheil Mohajerzefreh

Non-adaptive group testing involves grouping arbitrary subsets of

n

items into different pools. Each pool is then tested and defective items are identified. A fundamental question involves minimizing the number of pools required to identify at most

d

d ...

2012

Approximate Capacity of a Class of Gaussian Interference-Relay Networks

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh

In this paper, we study a Gaussian relay-interference network, in which relay (helper) nodes are to facilitate competing information flows between different source-destination pairs. We focus on two-stage relay-interference networks where there are weak cr ...

Institute of Electrical and Electronics Engineers2011

On the capacity of non-coherent network coding

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh, Mahdi Jafari Siavoshani

We consider the problem of multicasting information from a source to a set of receivers over a network where interme- diate network nodes perform randomized linear network coding operations on the source packets. We propose a channel model for the noncoher ...

2011

Graph-Constrained Group Testing

Amin Karbasi, Mahdi Cheraghchi Bashi Astaneh, Soheil Mohajerzefreh

Non-adaptive group testing involves grouping arbitrary subsets of

n

items into different pools and identifying defective items based on tests obtained for each pool. Motivated by applications in network tomography, sensor networks and infection propagati ...

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On Source Transmission over Deterministic Relay Networks

Suhas Diggavi, Soheil Mohajerzefreh

Lossless transmission of a set of correlated sources over a deterministic relay network is considered for two traffic requirements. In distributed multicast, the set of sources are to be delivered to a set of destinations. The source exchange requires all ...

2010

Asymmetric Multilevel Diversity Coding and Asymmetric Gaussian Multiple Descriptions

Suhas Diggavi, Soheil Mohajerzefreh

We consider the asymmetric multilevel diversity (A-MLD) coding problem, where a set of 2(K) - 1 information sources, ordered in a decreasing level of importance, is encoded into K messages (or descriptions). There are 2(K) - 1 decoders, each of which has a ...

2010

Approximation for Problems in Multi-User Information Theory

Soheil Mohajerzefreh

The main goal in network information theory is to identify fundamental limits of communication over networks, and design solutions which perform close to such limits. After several decades of effort, many important problems still do not have a characteriza ...

EPFL2010

On the Capacity of Non-Coherent Network Coding

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh, Mahdi Jafari

The min-cut value towards a single receiver in a network with unit capacity edges can be achieved by routing a single bit. The multicast theorem in network coding shows that, the common min-cut value towards N >= 1 receivers can also be achieved using pack ...

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Capacity of Deterministic Z-Chain Relay-Interference Network

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh

The wireless multiple-unicast problem is considered over a layered network, where the rates of transmission are limited by the relaying and interference effect. The deterministic model introduced in 131 is used to capture the broadcasting and multiple acce ...

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Approximating the Gaussian Multiple Description Rate Region Under Symmetric Distortion

Suhas Diggavi, Soheil Mohajerzefreh

We consider multiple description (MD) coding for the Gaussian source with K descriptions under the symmetric mean-squared error (MSE) distortion constraints, and provide an approximate characterization of the rate region. We show that the rate region can b ...

2009

On the capacity of multisource non-coherent network coding

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh, Mahdi Jafari Siavoshani

We consider multisource non-coherent network coding, where multiple sources send information to one or multiple receivers. We prove that this is equivalent to a ldquosubspacerdquo channel, that takes subspaces as inputs and outputs. We then show that the r ...

2009

A Deterministic Approach to Wireless Network Error Correction

Suhas Diggavi, Soheil Mohajerzefreh

In this paper we consider communication between two special nodes ("source" and "destination") in a wireless relay network, which has malfunctioning or malicious nodes (inserting errors). We develop the model for wireless network communication in the prese ...

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Transmission techniques for relay-interference networks

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh

In this paper we study the relay-interference wireless network, in which relay (helper) nodes are to facilitate competing information ﬂows over a wireless network. We examine this in the context of a deterministic wireless interaction model, which eliminat ...

2008

Asymmetric multi-level diversity coding

Suhas Diggavi, Soheil Mohajerzefreh

Symmetric multilevel diversity coding was introduced by Roche et al, where a set of K information sources is encoded by K encoders and the decoders reconstruct sources 1, . . . , k, where k is the number of encoders to which they have access. In this paper ...

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