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Li Z.R.,Communication University of China | Chen L.Y.,Communication University of China | Zhang H.,Communication University of China | Guo Q.X.,Communication University of China | And 4 more authors.
Journal of Electromagnetic Waves and Applications | Year: 2013

In this paper, the design, simulation results, and measurements of a coaxial-fed dual-polarized patch antenna with high port isolation are presented. The proposed antenna consists of two cross center-fed patch dipole antennas against a reflector as ground plane, while the patch antenna contains two pairs of X-shaped slots along the diagonals and two pairs of T-shaped slots along the centerlines. The proposed antenna achieves a-10 dB with bandwidth of 470-730 MHz and demonstrates the dual polarization in both directions. Stable radiation patterns at slanted polarization have been obtained within the band. Measurements show two linear polarizations with an isolation of more than 33 dB over the operating frequency band. The proposed antenna can be used for Digital television applications (DTV). © 2013 Taylor and Francis Group, LLC. Source


Mao J.Y.,Communication University of China | Li Z.R.,Communication University of China | Guo Q.X.,Communication University of China | Zhang H.,Communication University of China | And 3 more authors.
Journal of Electromagnetic Waves and Applications | Year: 2012

This paper presents the design and implementation of a novel Quasi-Yagi antenna with arrow-shaped driven element and a director for DTV applications. The proposed antenna has three resonant frequencies in the operating frequency band. Both simulation and measurement results show that the operating frequency bandwidth of the antenna for S11 < - 10 dB covers the DTV band (490-798 MHz), and the relative bandwidth is 48%. Far field measurements in azimuth plane and elevation plane show that the radiation patterns are stable and end-fire within the DTV band at frequencies of 530, 666 and 754 MHz. © 2012 Taylor & Francis. Source


Chen L.Y.,Communication University of China | Li Z.R.,Communication University of China | Zhang H.,Communication University of China | Zhang X.Q.,Beijing Research Institute of Chemical Defense | And 2 more authors.
Journal of Electromagnetic Waves and Applications | Year: 2012

A metal-plate monopole antenna for indoor digital television (DTV) signal coverage in the Ultra High Frequency (UHF) is presented. The proposed antenna is a planar metal-plate monopole with symmetrical bevels, which is easily fabricated by a single metal plate. Parametric study on the metal-plate parameters is conducted to achieve a return loss of 10 dB over the DTV band frequency range (470-860 MHz). The stability of the radiation pattern is also presented. © 2012 Taylor & Francis. Source


Xiao H.,Academy of Broadcasting Planning | Liu Q.,Tsinghua University | Dai Q.,Tsinghua University
Proceedings of the 10th International Conference on Mobile and Ubiquitous Multimedia, MUM'11 | Year: 2011

For resource-constrained wireless scenarios, this paper proposes a cooperative cross-layer scheme to improve the performance of scalable video transmission. At the application layer, the extraction parameters of scalable video coding are first optimized to maximize the visual quality and fulfill the resource constraints of decoding capacity and bandwidth. At the link layer, a priority-based cooperative scheduling strategy is further proposed to transmit the video packets of extracted substream. In this strategy, the relay link may substitute for the unreliable direct link if it has a relatively smaller packet error rate (PER). The packet priorities are determined by both the link PERs and the video layers properties. Simulations demonstrate the effectiveness of our proposed scheme. © 2011 ACM. Source


Tu Q.,Beijing University of Posts and Telecommunications | Feng J.,Academy of Broadcasting Planning | Qi J.,Beijing University of Posts and Telecommunications | Men A.,Beijing University of Posts and Telecommunications | Ye F.,Fujian Normal University
Proceedings - IEEE International Conference on Multimedia and Expo | Year: 2014

H.265/HEVC aims to provide significant improvement of compression performance compared with previous coding standards at cost of significant computation complexity. In this paper, an adaptive CU mode decision mechanism (ACMD) based on Bayesian decision theory is proposed to accelerate mode selection procedure. Specifically, the homogeneous determination is firstly utilized to filter out non-split LCU and then the feature space related to CU mode decision is introduced, which is divided into two regions according to Bayesian risk. Bayesian classifier is employed in low-risk region while in high-risk region, the mode decision is made by rate distortion cost. Experimental results demonstrate that the proposed algorithm provides averagely 34.28% encoding time reduction while maintaining the same level of perceptual visual quality, compared with HEVC test mode (HM 10.0) encoder with low-delay configurations. © 2014 IEEE. Source

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