Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Computer science. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

Statistical-QoS Driven Energy-Efficiency Optimization Over Green 5G Mobile Wireless Networks

Abstract: Since the Information and Communications Technologies (ICT) were designed without taking the energy-saving into account, the unexpected excessive energy consumption of the fourth-generation (4G) and pre-4G wireless networks causes serious carbon dioxide emissions. To achieve green wireless networks, the fifth-generation (5G) wireless networks are expected to significantly increase the network energy efficiency while guaranteeing the quality of service (QoS) for time-sensitive multimedia wireless traffics. In this paper, we develop the statistical delay-bounded QoS driven green power allocation schemes to maximize the effective power efficiency (EPE), which is defined as the statistical-QoS-guaranteed throughput (effective capacity) per unit power, over single-input single-output (SISO) and multipleinput multiple-output (MIMO)-channels based 5G mobile wireless networks. For the SISO-channel based 5G wireless networks, our developed QoS-driven green power allocation scheme converges to the despicking water-filling scheme (despicking channel inversion scheme) when the QoS constraint becomes very loose (stringent). We further develop and analyze the statistical-QoS-driven green power allocation scheme to maximize the EPE over the multiplexing-MIMO based 5G mobile wireless networks. The obtained numerical results show that our developed statistical QoS-driven green power allocation schemes can optimize the EPE over 5G mobile wireless networks, thus enabling the effective implementation of green 5G wireless networks.

Compact ultra-wideband antenna with tri-band notched characteristic

Abstract: A compact ultra-wideband printed planar antenna with tri-band notched characteristic is presented. Two different types of slots are used to obtain tri-band notched characteristic. By using a U-slot defected ground structure, a notched band, 5–6 GHz for WLAN, is achieved. An H-shaped slot is etched on the radiating patch to obtain another two notched bands at 3.3–3.7 GHz for WiMAX and 7.2 GHz for some C-band satellite communication systems. The proposed antenna yields an impedance bandwidth of 3.1–10.6 GHz with VSWR<2, except the notched bands. The antenna is successfully simulated and measured, showing tri-band notched characteristic can be obtained by using two different slots.

Elliptical-Arc-Fillet Flexure Hinges: Toward a Generalized Model for Commonly Used Flexure Hinges

Abstract: Flexure hinges have been used to produce frictionless and backlashless transmissions in a variety of precision mechanisms Although there are many types of flexure hinges available, designers often chose a single type of flexure hinge (eg, circular flexure hinges) without considering others in the design of flexure-based mechanisms This is because the analytical equations are unique to each kind of flexure hinge This work offers a solution to this problem in the form of a generalized flexure hinge model We propose a new class of flexure hinges, namely, elliptical-arc-fillet flexure hinges, which brings elliptical arc, circular-arc-fillet, elliptical-fillet, elliptical, circular, circular-fillet, and right-circular flexure hinges together under one set of equations The closed-form equations for all the elements in the compliance and precision matrices of elliptical-arc-fillet flexure hinges have been derived The analytical results are within 10 percent error compared to the finite element results and within 8 percent error compared to the experimental results The equations for evaluating the strain energy and stress level for elliptical-arc-fillet flexure hinges are also provided This model can be used as a complementary model for the generalized model for conic flexure hinges