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Full-Text Articles in Physical Sciences and Mathematics

Outage Constrained Robust Secure Transmission For Miso Wiretap Channels, Shuai Ma, Mingyi Hong, Engin Song, Xiangfeng Wang, Dechun Sun Oct 2014

Outage Constrained Robust Secure Transmission For Miso Wiretap Channels, Shuai Ma, Mingyi Hong, Engin Song, Xiangfeng Wang, Dechun Sun

Mingyi Hong

In this paper, we consider the robust secure beam-former design for multiple-input-single-output wiretap channels. Assuming that the eavesdroppers' channels are only partially available at the transmitter, we seek to maximize the secrecy rate under the transmit power and the secrecy rate outage probability constraint. The outage probability constraint requires that the secrecy rate exceed certain thresholds with high probability. Therefore, including such constraint in the design naturally ensures the desired robustness. Unfortunately, the presence of the probabilistic constraints makes the problem nonconvex and, hence, difficult to solve. In this paper, we investigate the outage probability constrained secrecy rate maximization problem …


Joint User Grouping And Linear Virtual Beamforming: Complexity, Algorithms And Approximation Bounds, Mingyi Hong, Zi Xu, Meisam Razaviyayn, Zhi-Quan Luo Oct 2013

Joint User Grouping And Linear Virtual Beamforming: Complexity, Algorithms And Approximation Bounds, Mingyi Hong, Zi Xu, Meisam Razaviyayn, Zhi-Quan Luo

Mingyi Hong

In a wireless system with a large number of distributed nodes, the quality of communication can be greatly improved by pooling the nodes to perform joint transmission/reception. In this paper, we consider the problem of optimally selecting a subset of nodes from potentially a large number of candidates to form a virtual multi-antenna system, while at the same time designing their joint linear transmission strategies. We focus on two specific application scenarios: 1) multiple single antenna transmitters cooperatively transmit to a receiver; 2) a single transmitter transmits to a receiver with the help of a number of cooperative relays. We …


Stability Of The Gyroid Phase In Diblock Copolymers At Strong Segregation, Eric W. Cochran, Carlos J. Garcia-Cervera, Glenn H. Fredrickson Mar 2006

Stability Of The Gyroid Phase In Diblock Copolymers At Strong Segregation, Eric W. Cochran, Carlos J. Garcia-Cervera, Glenn H. Fredrickson

Eric W. Cochran

The gyroid phase in diblock copolymers at strong segregation was stabilized. The intriguing topology of the network structure has inspired a diverse array of potential applications ranging from high-performance separation membranes to photonic crystals. The pressure field enforces incompressibility, while the exchange field is conjugate to the composition pattern in the melt. The Laplacian operator is treated implicitly with a fourth-order backward differentiation formula (BDF4), whereas the source term is discretized explicitly using fourth-order accurate Adams-Bashford.