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Huang W.,University of Science and Technology of China | Xiong Y.,University of Science and Technology of China | Li X.-Y.,Tsinghua University | Li X.-Y.,Illinois Institute of Technology | And 4 more authors.
Proceedings - IEEE INFOCOM

We propose an accurate acoustic direction finding scheme, Swadloon, according to the arbitrary pattern of phone shaking in rough horizontal plane. Swadloon tracks the displacement of smartphone relative to the acoustic direction with the resolution less than 1 millimeter. The direction is then obtained by combining the velocity from the displacement with the one from the inertial sensors. Major challenges in implementing Swadloon are to measure the displacement precisely and to estimate the shaking velocity accurately when the speed of phone-shaking is low and changes arbitrarily. We propose rigorous methods to address these challenges, and apply Swadloon to several case studies: Phone-to-Phone direction finding, indoor localization and tracking. Our extensive experiments show that the mean error of direction finding is around 2.1o within the range of 32m. For indoor localization, the 90-percentile errors are under 0.92m. For real-time tracking, the errors are within 0.4m for walks of 51m. © 2014 IEEE. Source

Wu Z.M.,Institute of Communication Engineering
7th International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2011

In this paper, a novel topology sequence calculation method is proposed and applied to track correlation algorithm. Based on attribute of topology sequence, tracks from different sensors will be same when there are no errors in sensor's measurement. In order to recognize track from blurred measurement, hypothesis verification is used. Detailed experimental results on such correlation algorithm confirm that topology sequence is robust to range and angle error of sensor measurement, not only including random error, but also including system error. © 2011 IEEE. Source

Wang H.,Institute of Communication Engineering | Song L.,Institute of Command Automation
Advanced Materials Research

Mobile peer to peer system in Ad hoc network is a brand novel application system. In this paper backgrounds and basic concepts of mobile peer to peer (p2p) systems are introduced firstly. Then possible applications of mobile p2p systems are expounded. Afterwards, technical challenges which mobile p2p system must face are analyzed in detail. In the end, the developments and implementation of mobile p2p system are explored and some conclusions are given. © (2011) Trans Tech Publications Switzerland. Source

He P.,Nanjing Institute of Technology | Xu Z.,Institute of Communication Engineering
ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings

Each node equipped with multiple interfaces in multi-channel wireless mesh networks can increase the network throughput when applied to appropriate channel assignment and routing protocols. In this paper, we analyze the channel assignment and channel switching problems in WMN where the number of interfaces is smaller than the number of channels. Ripple effect caused by channel switching is presented. The method to restrict the distance of ripple effect and to balance the load among channels is given. We also advance the Weighted Expected Residual Transmission Rate (WERTR) - a load-aware routing metric - to select a best quality route which is suitable for use with our proposed channel assignment strategy. © 2010 IEEE. Source

Li B.,Institute of Communication Engineering | Yang P.,Institute of Communication Engineering | Li X.-Y.,Illinois Institute of Technology | Tang S.,Illinois Institute of Technology | And 2 more authors.
Proceedings - IEEE INFOCOM

For cognitive wireless networks, one challenge is that the status of the channels' availability and quality is difficult to predict and quantify. Numerous learning based online channel sensing and accessing strategies have been proposed to address such challenge. In this work, we propose a novel channel sensing and accessing strategy that carefully balances the channel statistics exploration and multichannel diversity exploitation. Unlike traditional MAB-based approaches, in our scheme, a secondary cognitive radio user will sequentially sense the status of multiple channels in a carefully designed ordering. We formulate the online sequential channel sensing and accessing problem as a sequencing multi-armed bandit problem, and propose a novel policy whose regret is in optimal logarithmic rate in time and polynomial in the number of channels. We conducted extensive simulations to compare the performance of our method with traditional MAB-based approach. Our simulation results show that our scheme improves the throughput by more than 30% and speed up the learning process by more than 100%. © 2012 IEEE. Source

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