26,408 research outputs found
Outage Probability Analysis of Coded Cooperative Communication
Cooperative communication was proposed for wireless networks such as cellular network and wireless ad-hoc networks to meet the rapid increase in the data rate. Coded cooperative communication is one of the co-operative system, in which cooperation is combined with the channel coding. Coded cooperation is a promising technology to improve the outage performance of the system
Cooperation in Wireless Ad Hoc and Sensor Networks
Ministerio de Educación y Ciencia TIN2006-15617-C03-03 (AmbientNet)Junta de Andalucía P0-6TIC-2298 (SemiWheelNav)Junta de Andalucía P07-TIC-02476 (ARTICA
Cooperative wireless networks
In the last few years, there have been a lot of interests in wireless ad-hoc networks as
they have remarkable commercial and military applications. Such wireless networks
have the benefit of avoiding a wired infrastructure. However, signal fading is a severe
problem for wireless communications particularly for the multi-hop transmissions in
the ad-hoc networks. Cooperative communication has been proposed as an effective
way to improve the quality of wireless links. The key idea is to have multiple wireless
devices at different locations cooperatively share their antenna resources and aid
each other’s transmission.
In this thesis, we develop effective algorithms for cooperative wireless ad-hoc
networks, and the performance of cooperative communication is measured based
on various criteria, such as cooperative region, power ratio and end-to-end performance.
For example, the proposed interference subtraction and supplementary cooperation
algorithms can significantly improve network throughput of a multi-hop routing.
Comprehensive simulations are carried out for all the proposed algorithms and
performance analysis, providing quantitative evidence and comparison over other
schemes. In our view, the new cooperative communication algorithms proposed
in this research enable wireless ad-hoc networks to improve radio unreliability and
meet future application requirements of high-speed and high-quality services with
high energy efficiency. The acquired new insights on the network performance of
the proposed algorithms can also provide precise guidelines for efficient designs of
practical and reliable communications systems. Hence these results will potentially
have a broad impact across a range of related areas, including wireless communications,
network protocols, radio transceiver design and information theory
Generic Approaches for Node Co operation in Ad hoc Networks
In this paper, we review the approaches that uses the Generic methods to enforce cooperation in ad hoc routing. A very common assumption in the analysis and development of networking algorithms is the full co-operation of the participating nodes. However, the reality may differ considerably. The existence of multiple domains belonging to different authorities or even the selfishness of the nodes themselves could result in a performance that significantly deviates from the expected one. This review aims at providing the most popular Generic approaches to avoid selfishness in forwarding packets in ad hoc networks. This paper also discusses briefly the applications and issues in ad hoc wireless networks
Throughput-Delay Trade-off for Hierarchical Cooperation in Ad Hoc Wireless Networks
Hierarchical cooperation has recently been shown to achieve better throughput
scaling than classical multihop schemes under certain assumptions on the
channel model in static wireless networks. However, the end-to-end delay of
this scheme turns out to be significantly larger than those of multihop
schemes. A modification of the scheme is proposed here that achieves a
throughput-delay trade-off for T(n) between
and , where D(n) and T(n) are
respectively the average delay per bit and the aggregate throughput in a
network of n nodes. This trade-off complements the previous results of El Gamal
et al., which show that the throughput-delay trade-off for multihop schemes is
given by D(n)=T(n) where T(n) lies between and .
Meanwhile, the present paper considers the network multiple-access problem,
which may be of interest in its own right.Comment: 9 pages, 6 figures, to appear in IEEE Transactions on Information
Theory, submitted Dec 200
A cooperation-based approach to energy optimization in wireless ad hoc networks
A well known and still open issue for wireless ad hoc networks is the unfair energy consumption among the nodes. The specific position of certain nodes composing an ad hoc network makes them more involved in network operations than others, causing a faster drain of their energy. To better distribute the energy level and increase the lifetime of the whole network, we propose to periodically force the cooperation of less cooperative nodes while overwhelmed ones deliberately stop their service. A dedicated ad hoc network routing protocol is introduced to discover alternative paths without degradation in the overall network performance
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