213 research outputs found
Limited Feedback Scheme for Device to Device Communications in 5G cellular networks with Reliability and Cellular Secrecy Outage Constraints
In this paper, we propose a device to device (D2D) communication scenario
underlaying a cellular network where both D2D and cellular users (CUs) are
discrete power-rate systems with limited feedback from the receivers. It is
assumed that there exists an adversary which wants to eavesdrop on the
information transmission from the base station (BS) to CUs. Since D2D
communication shares the same spectrum with cellular network, cross
interference must be considered. However, when secrecy capacity is considered,
the interference caused by D2D communication can help to improve the secrecy
communications by confusing the eavesdroppers. Since both systems share the
same spectrum, cross interference must be considered. We formulate the proposed
resource allocation into an optimization problem whose objective is to maximize
the average transmission rate of D2D pair in the presence of the cellular
communications under average transmission power constraint. For the cellular
network, we require a minimum average achievable secrecy rate in the absence of
D2D communication as well as a maximum secrecy outage probability in the
presence of D2D communication which should be satisfied. Due to high complexity
convex optimization methods, to solve the proposed optimization problem, we
apply Particle Swarm Optimization (PSO) which is an evolutionary approach.
Moreover, we model and study the error in the feedback channel and the
imperfectness of channel distribution information (CDI) using parametric and
nonparametric methods. Finally, the impact of different system parameters on
the performance of the proposed scheme is investigated through simulations. The
performance of the proposed scheme is evaluated using numerical results for
different scenarios.Comment: IEEE Transactions on Vehicular Technology, 201
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
Physical layer security for machine type communication networks
Abstract. We examine the physical layer security for machine type communication networks and highlight a secure communication scenario that consists of a transmitter Alice, which employs Transmit Antenna Selection, while a legitimate receiver Bob that uses Maximum Ratio Combining, as well as an eavesdropper Eve. We provide a solution to avoid eavesdropping and provide ways to quantify security and reliability. We obtain closed-form expressions for Multiple-Input Multiple-Output and Multi-antenna Eavesdropper (MIMOME) scenario. The closed{-}form expressions for three useful variations of MIMOME scenario, i.e., MISOME, MIMOSE, and MISOSE are also provided. A low cost and less complex system for utilizing the spatial diversity in multiple antennas system, while guaranteeing secrecy and reliability. Similarly, it is also assumed that Alice, Bob, and Eve can estimate their channel state information, and then we evaluate the performance of closed-form expressions in terms of secrecy outage probability and provide Monte Carlo simulations to corroborate the proposed analytical framework
Beamforming Techniques for Non-Orthogonal Multiple Access in 5G Cellular Networks
In this paper, we develop various beamforming techniques for downlink
transmission for multiple-input single-output (MISO) non-orthogonal multiple
access (NOMA) systems. First, a beamforming approach with perfect channel state
information (CSI) is investigated to provide the required quality of service
(QoS) for all users. Taylor series approximation and semidefinite relaxation
(SDR) techniques are employed to reformulate the original non-convex power
minimization problem to a tractable one. Further, a fairness-based beamforming
approach is proposed through a max-min formulation to maintain fairness between
users. Next, we consider a robust scheme by incorporating channel
uncertainties, where the transmit power is minimized while satisfying the
outage probability requirement at each user. Through exploiting the SDR
approach, the original non-convex problem is reformulated in a linear matrix
inequality (LMI) form to obtain the optimal solution. Numerical results
demonstrate that the robust scheme can achieve better performance compared to
the non-robust scheme in terms of the rate satisfaction ratio. Further,
simulation results confirm that NOMA consumes a little over half transmit power
needed by OMA for the same data rate requirements. Hence, NOMA has the
potential to significantly improve the system performance in terms of transmit
power consumption in future 5G networks and beyond.Comment: accepted to publish in IEEE Transactions on Vehicular Technolog
Security for 5G Mobile Wireless Networks
The advanced features of 5G mobile wireless network systems yield new security requirements and challenges. This paper presents a comprehensive survey on security of 5G wireless network systems compared to the traditional cellular networks. The paper starts with a review on 5G wireless networks particularities as well as on the new requirements and motivations of 5G wireless security. The potential attacks and security services with the consideration of new service requirements and new use cases in 5G wireless networks are then summarized. The recent development and the existing schemes for the 5G wireless security are presented based on the corresponding security services including authentication, availability, data confidentiality, key management and privacy. The paper further discusses the new security features involving different technologies applied to 5G such as heterogeneous networks, device-to-device communications, massive multiple-input multiple-output, software defined networks and Internet of Things. Motivated by these security research and development activities, we propose a new 5G wireless security architecture, based on which the analysis of identity management and flexible authentication is provided. As a case study, we explore a handover procedure as well as a signaling load scheme to show the advantage of the proposed security architecture. The challenges and future directions of 5G wireless security are finally summarized
Secure D2D Communication in Large-Scale Cognitive Cellular Networks: A Wireless Power Transfer Model
In this paper, we investigate secure device-to-device (D2D) communication in energy harvesting large-scale cognitive cellular networks. The energy constrained D2D transmitter harvests energy from multi-antenna equipped power beacons (PBs), and communicates with the corresponding receiver using the spectrum of the primary base stations (BSs). We introduce a power transfer model and an information signal model to enable wireless energy harvesting and secure information transmission. In the power transfer model, three wireless power transfer (WPT) policies are proposed: 1) cooperative power beacons (CPB) power transfer, 2) best power beacon (BPB) power transfer, and 3) nearest power beacon (NPB) power transfer. To characterize the power transfer reliability of the proposed three policies, we derive new expressions for the exact power outage probability. Moreover, the analysis of the power outage probability is extended to the case when PBs are equipped with large antenna arrays. In the information signal model, we present a new comparative framework with two receiver selection schemes: 1) best receiver selection (BRS), where the receiver with the strongest channel is selected, and 2) nearest receiver selection (NRS), where the nearest receiver is selected. To assess the secrecy performance, we derive new analytical expressions for the secrecy outage probability and the secrecy throughput considering the two receiver selection schemes using the proposed WPT policies. We presented Monte-carlo simulation results to corroborate our analysis and show: 1) secrecy performance improves with increasing densities of PBs and D2D receivers due to larger multiuser diversity gain, 2) CPB achieves better secrecy performance than BPB and NPB but consumes more power, and 3) BRS achieves better secrecy performance than NRS but demands more instantaneous feedback and overhead. A pivotal conclusion is reached that with increasing number of antennas at PBs, NPB offers a comparable secrecy- performance to that of BPB but with a lower complexity
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