Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey

This paper provides a comprehensive review of the domain of physical layer security in multiuser wireless networks. The essential premise of physical-layer security is to enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers without relying on higher-layer encryption. This can be achieved primarily in two ways: without the need for a secret key by intelligently designing transmit coding strategies, or by exploiting the wireless communication medium to develop secret keys over public channels. The survey begins with an overview of the foundations dating back to the pioneering work of Shannon and Wyner on information-theoretic security. We then describe the evolution of secure transmission strategies from point-to-point channels to multiple-antenna systems, followed by generalizations to multiuser broadcast, multiple-access, interference, and relay networks. Secret-key generation and establishment protocols based on physical layer mechanisms are subsequently covered. Approaches for secrecy based on channel coding design are then examined, along with a description of inter-disciplinary approaches based on game theory and stochastic geometry. The associated problem of physical-layer message authentication is also introduced briefly. The survey concludes with observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials, 201

Online auction-based relay selection for cooperative communication in CR networks

Cognitive radio and cooperative communication are two new network technologies. So, the combination of these two new technologies is a novel solution to solve the problem of spectrum scarcity. Two main challenges exist in the integration of cognitive radio and cooperative communication. First, there is a lack of incentives for the participating wireless devices to serve as relay nodes. Second, there is not an effective relay selection policy. In this paper, we propose an online auction-based relay selection scheme for cooperative communication in cognitive radio (CR) networks. Specifically, we design an auction scheme through adopting stopping theory. The proposed scheme ensures that the primary user (PU) can effectively select a CR relay to transmit its packets in a given time bound. In addition, we have analytically proven the truthfulness and the individual rationality of our online auction scheme. Extensive simulations demonstrate that the proposed relay selection scheme can always successfully and efficiently select a proper relay for a PU and can achieve a higher cooperative communication throughput compared with the conventional schemes

A Survey on Dynamic Spectrum Sharing Using Game Theory in Cognitive Radio Networks

Due to the tremendous increase in wireless data traffic, a usable radio spectrum is quickly being depleted. Current Fixed Spectrum Allocation (FSA) strategy give rise to the problem of spectrum scarcity and underutilization. Cognitive Radio (CR) is proposed as a new wireless paradigm to overcome the spectrum underutilization problem. CR is a promising technology which for future wireless communications. CRs can change its operating parameters intelligently in real time to account for dynamic changes in a wireless environment. CR enables a technique called Dynamic Spectrum Allocation (DSA) where the users are able to access unlicensed bands opportunistically. Since idle spectrum from PU is a valuable commodity, many cognitive users will be competing for it simultaneously. Therefore, there arises competition among the users. Users may be only concerned about maximizing their own benefits by behaving rationally and selfishly. Thus spectrum allocation problem falls under NP-hard complex based on its complexity to solve. Out of several solution approaches, Game theory is found to be an efficient mathematical tool since it deals with solving the conflicts among the users. This survey is aimed at providing a comprehensive overview on dynamic spectrum allocation using game theory