Penn State College of Communications

About: Penn State College of Communications is a based out in . It is known for research contribution in the topics: Relay & Cognitive radio. The organization has 2106 authors who have published 2119 publications receiving 24693 citations.

Performance Analysis of Two-Way Satellite Terrestrial Relay Networks With Hardware Impairments

Abstract: In this letter, the effect of hardware impairments on two-way satellite-terrestrial hybrid relay networks is analyzed. The terrestrial relay is considered as a two-way relay, which can transmit signals to both the satellite source and the mobile source simultaneously. Specifically, the closed-form expression, the asymptotic expression at high signal-to-noise rates and the throughput for the considered system are derived. The expressions show that the impairments greatly affect the system performance and system performance will be worse when the impairment level is larger. In addition, numerical results are provided to show the correctness of the analytical results.

Stochastic computation offloading game for mobile cloud computing

Abstract: With the growing popularity of mobile applications, mobile cloud computing has been envisioned as a promising approach to help mobile devices enhance computation capability and reduce energy consumptions. In this paper, we investigate the problem of multi-user computation offloading for mobile cloud computing under dynamic environment, wherein mobile users may become active or inactive (i.e., silent) dynamically, and the wireless channels for users to offload computation vary randomly. Taking into account the mutual interference among different users when offloading computation to mobile could via wireless channels, we formulate the mobile users' offloading decision process as a stochastic game. We further prove that the formulated stochastic game is equivalent to a potential game which has at least one Nash Equilibrium (NE). At the NE, no single user will unilaterally change its computation offloading strategy. Furthermore, we propose a multi-agent stochastic learning algorithm to reach the NE with guaranteed convergence. Finally, we conduct simulations to validate the effectiveness of the proposed algorithm and evaluate its performance under dynamic environment.

Energy-Efficient Covert Communications for Bistatic Backscatter Systems

Abstract: In this paper, we consider covert communications for bistatic backscatter systems, where a tag transmits information passively to a reader by reflecting incident carrier signals with artificial noise (AN) generated from a dedicated carrier emitter (CE) under the supervision of a warden. By exploiting the channel uncertainty introduced by CE, we analytically derive the warden's minimum sum of error probabilities to evaluate communication covertness. We find that communication covertness can be improved by reducing the tag's reflection coefficient, but is not affected by the CE's transmit power. Therefore, in order to achieve energy-efficient design, we optimize the tag's reflection coefficient to minimize the CE's transmit power under the constraints of communication covertness and reliability. Our analysis shows that the minimum CE's transmit power can be further reduced with a minor loss of the achievable covert rate.

Ultrafast quantum computation in ultrastrongly coupled circuit QED systems.

Abstract: The latest technological progress of achieving the ultrastrong-coupling regime in circuit quantum electrodynamics (QED) systems has greatly promoted the developments of quantum physics, where novel quantum optics phenomena and potential computational benefits have been predicted. Here, we propose a scheme to accelerate the nontrivial two-qubit phase gate in a circuit QED system, where superconducting flux qubits are ultrastrongly coupled to a transmission line resonator (TLR), and two more TLRs are coupled to the ultrastrongly-coupled system for assistant. The nontrivial unconventional geometric phase gate between the two flux qubits is achieved based on close-loop displacements of the three-mode intracavity fields. Moreover, as there are three resonators contributing to the phase accumulation, the requirement of the coupling strength to realize the two-qubit gate can be reduced. Further reduction in the coupling strength to achieve a specific controlled-phase gate can be realized by adding more auxiliary resonators to the ultrastrongly-coupled system through superconducting quantum interference devices. We also present a study of our scheme with realistic parameters considering imperfect controls and noisy environment. Our scheme possesses the merits of ultrafastness and noise-tolerance due to the advantages of geometric phases.

Massive MIMO for Distributed Detection With Transceiver Impairments

Abstract: This paper investigates an issue of massive MIMO-based distributed detection that considers transceiver hardware impairments at both a massive-antenna fusion center (FC) and multiple single-antenna sensors. First, we derive closed-form expressions of the probability of detection and the probability of false alarm, and show that hardware impairments create finite ceilings on the achievable detection performance. Then, we formulate a constrained optimization problem as sum of linear ratios programming to maximize the detection probability. By exploiting the inherent problem structures, we further develop an algorithm based on the alternating direction method of multipliers. Extensive simulations demonstrate that the nonideal hardware has a fundamental impact on the distributed detection performance. More specifically, in the limit of an infinite number of antennas and infinite sensor reporting power budget, the effects of FC impairment and FC receiver noise vanish, while the sensor impairment dominates the achievable distributed detection performance.