The use of existing network devices as relays has a potential to improve the overall network performance. In this work, we consider a two-hop wireless relay setting, where the channels between the source and relay nodes to the destination node are time varying. The relay nodes are able to overhear the transmissions of the source node which may have a weak connection to the destination, and they...

Cooperative relaying enables nodes to actively cooperate to deliver packets to their destination. The best-select protocol (BSP) implements a type of cooperative relaying that generalizes single path routing with sets of nodes (relay-sets) replacing the concept of a single node relay. Thus, while in traditional single path routing, packets hop from node to node, in BSP, packets hop from relay-s...

In wireless networks, it has always been a challenge to satisfy high traffic throughput demands, due to limited spectrum resources. In past decades, various techniques, including cooperative communications, have been developed to achieve higher communication rates. This thesis addresses the challenges imposed by cooperative wireless networks, in particular focusing on practical code constructio...

Recently, multiple-input multiple-output (MIMO) relay technique has been received great attention due to its prominent ability to provide broad coverage and enhance the link reliability and spectral efficiency. In this paper, an overview of optimal design for single user and multiuser non-regenerative MIMO relay systems is proposed. We explore some key designs of source node and destination nod...

In this study, two hop non-regenerative Multiple Input Multiple Output (MIMO) relay network is considered. Each node of the network is equipped with multiple antennas. We apply an efficient linear processing at the relay node only. We utilize Minimum Mean Square Error (MMSE) as the relay receive beamforming and PerAntenna-Signal to Leakage plus Noise Ratio (PA-SLNR) maximization criteria using ...

ABSTRACT In multihop wireless networks, packets of a flow originated from a source node are relayed by intermediate nodes (relay nodes) and travel towards the destination along a multihop wireless path. Since the traffic forwarding capability of each node varies according to its level of contention, a node should not transmit excessive packets to its relay node if the corresponding relay node c...

In wireless sensor networks nodes follows sleepwake cycling policy. If a node wants to forward the packet to another node, it has to select a node from available nodes. Each relay is associated with a reward that gives the benefit of forwarding the packet using that relay. We have to develop a solution to this local problem, if that solution is adopted by every node, it should provide a reasona...

In order to provide randomized routing ALERT (Anonymous Location-based and Efficient Routing) protocol is used. But the proposed protocol SEALERT will provide higher anonymity protection at lower cost. It also increases the nodal lifetime in the network. Thereby it increases the efficiency of transmission of packets. The proposed protocol dynamically partitions the network into area called zone...

In this paper, a cooperative algorithm to improve the orthogonal space-timefrequency block codes (OSTFBC) in frequency selective channels for 2 1, 2 2, 4 1, 4 2 MIMO-OFDM systems, is presented. The algorithm of three node, a source node, a relay node and a destination node is formed, and is implemented in two stages. During the first stage, the destination and the relay antennas receive the sym...

This paper proposes a new relay selection scheme for wireless cooperative networks that effectively distributes the traffic of packets from the source nodes to the sink. By estimating the channel information of the two-hop neighbors, the source node can choose the most optimal relay node to forward its messages on the basis of the transmission rate of the channels from the source to the relay a...