This paper considers a fully-connected interference network with a relay in which multiple users equipped with a single antenna want to exchange multiple unicast messages with other users in the network by sharing the relay equipped with multiple antennas. For such a network, the degrees of freedom (DoF) are derived by considering various message exchange scenarios: a multi-user fullyconnected ...

Nowadays, providing higher data rate is a momentous goal for wireless communications systems. Interference is one of the important obstacles to reach this purpose. Interference alignment is a management technique that align interference from other transmitters in the least possible dimension subspace at each receiver and as a result, provide the remaining dimensions for free interference signal...

System Design and Outage Analysis for Cooperative Diversity Wireless Networks by Sungjoon Park Chair: Wayne E. Stark Relay communication systems have recently been gaining momentum as an alternative to cellular architectures because of the ability to provide cost-efficient high spectral efficiency communications. The goal of this thesis is to investigate opportunistic relay communication strate...

A non-regenerative dual-hop wireless system based on a distributed space-time-coding strategy is considered. It is assumed that each relay station retransmits an appropriate scaled space-time coded version of the received signals. The main goal of this paper is to provide an analytical study of an optimum power allocation strategy in relay stations in order to satisfy the quality of service req...

A multiple access relay channel (MARC) is considered in which an analogue-like network coding is implemented in the relay node. This analogue coding is a simple addition of the received signals at the relay node. Using “nulling detection” structure employed in V-BLAST receiver, we propose a detection scheme in the destination which is able to provide a diversity order of two for all users. We a...

Most works on amplify and forward (AF) relaying assume that the relay obtains perfect channel state information (CSI) of the source-relay channel. This renders variable-gain relaying (VGR) an attractive technique, as the relay can ideally invert the channel at its input and thus ensure constant output power. What happens to the output power, however, if the CSI at the input is outdated? As an a...

This paper investigates the superposition-based cooperative transmission system. In this system, a key point is for the relay node to detect data transmitted from the source node. This issued was less considered in existing literature as the channel is usually assumed to be flat fading and a priori known. In practice, however, the channel is not only a priori unknown but subject to frequency se...

Wireless Relaying is a promising solution to overcome the channel impairments and provides high data rate coverage that appears for beyond 3G mobile communications. In this paper we present end to end BER performance of dual hop wireless communication systems equipped with multiple Decode and Forward relays over Rayleigh fading channel with the best relay selection. We compare the BER performan...

This paper studies the Degrees of Freedom (DoF) of the two-user multi-antenna Gaussian interference channel with an instantaneous relay, or relay without delay, where the relay transmitted signal in channel use t can depend on all received signals up to and including that at channel use t. It is assumed that the two transmitters and the two receivers have M antennas, while the relay receives th...