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.

Toward 5G: A Novel Sleeping Strategy for Green Distributed Base Stations in Small Cell Networks

Abstract: Confronted with the rapidly increasing demand of mobile traffic and heavy energy consumption on base stations (BSs), the base station (BS) sleeping strategy becomes a promising method to promote the system energy efficiency (EE). To switch off the redundant small-cell base stations (s-BSs) without whittling down the network EE in small cell networks, we propose a novel environment-friendly distributed BS sleeping strategy, which consists of two parts, matching and connecting between the s-BSs and the user equipments (UEs), and activating the BS-turning-off procedure for the further promotion of EE. An initializing matching connection algorithm (IMCA) is proposed for the first subproblem and the energy efficiency ratio (EER) obtained by this proposed IMCA surpasses the EE gained from traditional initializing random connection method. Moreover, a turn-off if possible algorithm (TIPA) is proposed as the sleeping strategy to handle the BS-turning-off procedure. Both the EE and the convergence speed obtained by the sleeping deployment using TIPA surpass those of the traditional best response algorithm.

Security Analysis of QAM Quantum-Noise Randomized Cipher System

Abstract: Applying the quadrature amplitude modulation (QAM) format, quantum-noise randomized cipher (QNRC) systems hide the signal states in quantum phase noise and amplitude noise to prevent eavesdropping. In this paper, based on the traditional wire-tap channel model analysis method, the physical-layer security of QAM-QNRC system is investigated quantitatively under the metric of secrecy rate. The general expressions of secrecy rates of the data and key are derived separately. Furthermore, the maximum reachable secrecy rate of a QAM-QNRC system is put forward, under which the data and key are both safe in the view of mutual information evaluation. Finally, the variation trend of secrecy rate with various system parameters is discussed in detail. The simulation results show that we can obtain a higher secrecy rate by setting reasonable parameters, such as the level of ciphertext, mesoscopic signal power, and inner gain at the transmitter. Meanwhile, the security of the key is the main constraint of the maximum reachable secrecy rate.

Sliding mode controller based on fuzzy neural network optimization for direct torque controlled PMSM

Abstract: A sliding mode controller for permanent magnet synchronous machine (PMSM) is investigated in this paper, in which direct torque control (DTC) concept, variable structure control and space vector modulation (SVM) are integrated to achieve high performance. It features in very low flux and torque ripple, strong robustness and fixed switching frequency. Then, an FNN is investigated to optimize the control gain matrix of sliding mode controller. The inputs of the FNN are the switching surface and its derivative, and the output of the FNN is the estimated bound of uncertainties. The theoretical analyses for the proposed FNN sliding-mode controller are described in detail. Simulation results show that the proposed FNN sliding-mode controller provides high-performance dynamic characteristics and is robust with regard to plant parameter variations. Furthermore, comparing with the sliding-mode controller, the chattering phenomenon is much reduced by the proposed FNN sliding-mode controller.

Secure Communication for Amplify-and-Forward Relay Networks With Finite Alphabet Input

Abstract: This paper considers secure communication for amplify-and-forward (AF) relay networks with finite alphabet input. The joint optimization of power selection and beamforming design for improving the physical layer security of AF relay networks with single and multiple eavesdroppers is investigated. For the case with one eavesdropper, we transform the problem of multi-variable beamforming design into a single-variable optimization problem through semi-definite programming and solve it with one-dimensional optimization techniques. Moreover, the corresponding source power is obtained by utilizing the relation between the mutual information and minimum mean square error. Then, an iterative two-step algorithm is proposed to maximize the achievable secrecy rate. In the presence of multiple eavesdroppers, a zero-forcing beamforming scheme, where the confidential signal is nulled out in the direction of all eavesdroppers, is proposed to enhance the physical layer security. We decouple the source power and the beamforming vector by transforming the achievable secrecy rate into a single-variable function of the source power. Then, the suboptimal source power and the corresponding beamforming vector with low-complexity are derived. Numerical examples show that the proposed schemes significantly enhance the secrecy performance of the AF relay networks.