Relay selection has been regarded as an effective method to improve the performance of cooperative communication system. However, frequent operation of relay selection can bring enormous control message overhead and thereby decrease the performance of cooperative communication. To reduce the relay selection frequency, in this paper, we propose a relay selection scheme to choose the best relay w...

Simultaneous wireless information and power transfer (SWIPT) is a promising new solution to provide a perpetual lifetime for energy constrained nodes in wireless networks. In this paper, we consider a wireless sensor relay network, where relay nodes forward a radio frequency (RF) signal from a source node to a destination node by first harvesting energy from the RF signal. For multiple relay no...

This paper explores the relay selection scheme for two-way relay channels with physical layer network coding (PNC), where two end nodes exchange information via a selected relay node with the minimal symbol error rate (SER) performance among multiple candidate relay nodes. To reduce the computational complexity, we also propose a suboptimal minimal SER-based relay selection. The end-to-end SER ...

This thesis is devoted to studying two wireless relay network models, namely wireless tandem multiple-input-multiple-output (MIMO) relay networks and wireless two-hop multicast relay networks. Regarding wireless tandem MIMO relay networks, we develop a systematic approach to analyze their fundamental diversity-multiplexing tradeoff (DMT) under the assumption that the relays implement a class of...

This paper deals with the problem of multicasting a set of discrete memoryless correlated sources (DMCS) over a cooperative relay network. Necessary conditions with cut-set interpretation are presented. A Joint source-Wyner-Ziv encoding/sliding window decoding scheme is proposed, in which decoding at each receiver is done with respect to an ordered partition of other nodes. For each ordered par...

This paper analyzes the performance of cooperative amplify-and-forward (CAF) relay networks that employ adaptive M-ary quadrature amplitude modulation (M-QAM)/M-ary phase shift keying (M-PSK) digital modulation techniques in Nakagami-m fading channel. In particular, we present and compared the analysis of CAF relay networks with different cooperative diversity and opportunistic routing strategi...

Nodes in mobile ad hoc networks have limited transmission ranges that necessitate multihop communication. Hence the nodes expect their neighbours to relay the packets meant for nodes out of the transmission range of the source. Ad hoc networks are based on the fundamental assumption that if a node promises to relay a packet, it will relay the packet and will not cheat. This assumption becomes i...

Delay tolerant networks (DTNs) rely on the mobility of nodes and sequences of their contacts to compensate for lack of continuous connectivity and thus enable messages to be delivered from end to end in a “store-carry-forward” way, where multiple relay nodes are usually employed in the message delivery process. In this paper, we focus on such relay cooperation and analytically explore its impac...

Wireless sensor networks have been a big promise during the last few years, but a lack of real applications makes difficult the establishment of this technology. Monitoring the environment in collection and sending data is considered to be a ridiculous task. To solve this problem, RAF based Energy Efficient Routing and Environment Monitoring via Mobile Sensors is proposed in Mobile Wireless Sen...

In this paper, a cooperative protocol is proposed for wireless mesh networks. Two features are implemented: on-demand cooperation and selection of the best relay. First, cooperation is activated by a destination terminal when it fails in decoding the message from a source terminal. Second, a selection of the best relay is performed when cooperation is needed. The robustness of wireless links ar...