M.Sc Thesis

M.Sc StudentDikshtein Michael
SubjectInformation Theoretic Aspects of Device to Device
DepartmentDepartment of Electrical and Computer Engineering
Supervisor Shlomo Shamai )Shitz(
Full Thesis textFull thesis text - English Version


Technological advances in the fields of mobile devices processing capabilities, high resolution cameras and displays have enabled high-definition video streaming applications. As a result, those devices produce a considerable network load. A recent report has shown that video accounted for 58\% of the total downstream volume of traffic on the Internet. Furthermore, evolution of Internet of Things, Vehicle-to-Vehicle and Vehicle-to-Infrastructure communication, Augmented Reality, Unmanned Aerial Vehicles and Wearable Medical Devices, have all put challenge on the cellular network systems. Hence, next-generation cellular networks are required to support very high throughput, low latency and massive connectivity.

Conventional cellular systems, from the first generation up until current 4G, share the physical resources, such as time, frequency, power, in an orthogonal manner between the users. Although such an approach enables interference-free communication links, its achievable rate fall behind those promised by Multiuser Information Theory results. Thus, to support more users and higher communication rates, new network topologies are under extensive research where the most promising strategy is to include cooperation between the various nodes of the network.

In this study, we consider a simple model of cooperation between mobile users. In particular, we address the problem of channel coding over multi-terminal state dependent channels in which only one node has a noncausal knowledge of the state. Such channel models arise in many emerging communication schemes. We start by investigating the parallel-state dependent channel with same but differently scaled states where there is a cognitive helper which knows the state in noncausal manner and wishes to mitigate the interference, modeled as state, that impacts the transmission between two transmit-receive pairs. Outer and inner bounds are derived. Then the channel parameters are partitioned into various cases, and segments on the capacity region boundary are characterized for each case. Furthermore, we show, that for a special set of channel parameters, the capacity region is entirely characterized.

In the second part of this thesis, following the last paragraph, we address a similar scenario, but now each channel is corrupted by an independent state. We derive an inner bound using a coding scheme that integrates single bin Gelfand-Pinsker coding and Marton's coding for the broadcast channel. We also derive an outer bound and further partition the channel parameters into several cases for which parts of the capacity region boundary are characterized.

Information secrecy is a major factor in design consideration of a wireless system. In the last part of this work, we study the problem of analog secrecy and digital information conveying. Such scenario frequently arises in situations where the broadcasting node wishes to transmit reliably coded information solely and want to hide the uncoded transmission from the receivers. Specifically, we address the problem of coding over the general discrete memoryless state-dependent broadcast channel  with an additional requirement of masking the state.  We derive inner and outer bounds for the general discrete memoryless case and show that they are tight for a special case of private messages transmission over a scalar Gaussian broadcast channel.