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Performance evaluation of channel inversion precoding for downlink multi-user MIMO system

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The Journal of China Universities of posts and telecommunications 2009年第5期16卷 20-24页

作者： CHEN Zhi-yong , WANG Wen-bo, PENG Mu-gen, LI Ren Wireless Signal Processing and Network Laboratory, Key Laboratory of Universal Wireless Communication, Ministry of Education, beijing university of posts and telecommunications, beijing 100876, China Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In downlink multi-user multi-input multi-output （MU-MIMO） system, not every user （user equipment （UE）） can calculate accurately signal to interference and noise ratio （SINR） without prior knowledge of the other users＇ precoding vector. To solve this problem, this article proposes a channel inversion precoding scheme by using the lower bound of S1NR and zero-forcing （ZF） algorithm. However, the SINR mismatch between lower bound SINR and actual SINR causes the inaccurateness of adaptive modulation and coding （AMC）. As a result, it causes degradation in performance. Simulation results show that channel inversion precoding provides lower throughput than that of single user multi-input multi-output （SU-MIMO） at high signal-to-noise ratio （SNR）（〉14 dB）, due to the SINR mismatch, although the sum-rate of channel inversion precoding is higher than that of SU-MIMO at full SNR regime.

关键词： MU-MIMO channel inversion precoding CQI feedback AMC lower bound S1NR zero-forcing

Decoding algorithms for shortened-extended turbo product codes in WiMAX systems

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science in China(Series F) 2009年第12期52卷 2415-2423页

作者： XU ChangLong1,3.4, YANG Wei1,2 & YE WeiChen4 1 State Key Laboratory of Networking and Switching Technology, beijing university of posts and telecommunications, beijing 100044, China 2 State Key Laboratory of Rail Traffic Control and Safety, beijing Jiaotong{3., beijing 100044, China 3.National Mobile Communications Research Laboratory, Southeast{3., Nanjing 210096, China 4 Intel Corporation, beijing Kerry Center, Guanghua Road 1, beijing 100020, China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China National Mobile Communications Research Laboratory Southeast University Nanjing China Intel Corporation Beijing Kerry Center Beijing China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China

The component codes of turbo product codes in WiMAX systems are extended Hamming codes and single parity check codes as well as their shortened forms, In this paper, three novel iterative decoding algorithms based on Chase, MAP algorithms and their combination are proposed for shortened-extended turbo product codes. The iterative decoding algorithm based on Chase algorithm is proposed to reduce the decoding complexity without any performance loss. An efficient MAP algorithm is then proposed to decode the component codes of shortened single parity check codes and shortened-extended Hamming codes. A comprehensive performance comparison of the proposed decoding schemes is conducted for three typical classes of turbo product codes in WiMAX OFDMA systems. The suitable decoding algorithms are recommended for different classes based on the simulation results.

关键词： block code product code iterative decoding

A New Wavelength Selective Photoreceiver

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Chinese Journal of Lasers 2000年第5期9卷 51-55页

作者： LIU Kai HUANG Yongqing REN Xiaomin LI Jianxin GUO Wei (Optical Communication Center, beijing university of posts and telecommunications, beijing 100876, China)MA Xiaoyu KANG Xuejun LIAO Qiwei (Institute of Semiconductor, The Chinese Academy of 北京邮电大学北京中科院半导体所北京

A new kind of wavelength selective photoreceiver is proposed. It was constructed by a Fabry Perot (F P) etalon filter and a resonant cavity enhanced (RCE) photodetector. The photoreceiver′s spectral response is determined by the F P etalon filter with a FWHM of less than 4 nm. Moreover, with such a photoreceiver, the transmission loss of the F P etalon filter can be compensated to some extent. And this will benefit its applications.

关键词： wavelength selection photodetector WDM and optoelectronics device

Investigation of Architecture and Essential Technologies of Wireless Sensor Network

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ZTE Communications 2005年第4期3卷 25-32页

作者： Peng Mugen, Wang Yingjie, Wang Wenbo (school of telecommunications Engineering, beijing university of posts and telecommunications,{3., China)

This paper introduces the architecture of wireless sensor networks, presents a cross-layer network management and control mechanism. The key technologies, such as Medium Access Control (MAC) and wireless routing protocols are discussed and compared. A proposal of applying the simple IEEE 802 MAC protocol into the wireless sensor network is introduced. In addition, in order to improve the system capacity, a multi-channel strategy for the sensor nodes is presented for decreasing the blocking probability and suppressing the accessing time delay. It is concluded that there are still a number of problems to be solved, including decreasing power consumption, improving capacity and avoiding access collision, to promote the successful commercial application of wireless sensor network.

关键词： IEEE WSN Investigation of Architecture and Essential Technologies of Wireless Sensor Network node MAC

Research on Trilateral Game among Owner,Contractor and Engineering Supervisor in Communication Construction Market

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Research on Trilateral Game among Owner,Contractor and Engin...

IP over ATM Implementation with Local Switch Mode

2010 Chinese Control and Decision Conference

作者： Yumei Zhao~1,Rong Hua~2,Xiaodong Zhang~3.Yaxian Li~4 1.school of Economics and Management,beijing university of{3.&telecommunications,beijing,100876 2.school of Economics and Management,beijing university of{3.&telecommunications,beijing,100876

＜正＞This paper combines principal-agent theory with rent-seeking theory,comprehensively analyzes the relationships among owner,supervisor and contractor,utilizes game theory to establish the model of owners,supervisor and contractor,and analyzes the game behavior or rent-seeking between supervisor and *** paper adds the long-term economic benefits and reputation of supervisor and contractor into the tripartite game model,and proposes some constructive comments.

关键词： Rent-seeking Risk Management Trilateral Game Communication Construction market

来源： cnki会议评论

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cnki会议

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The Journal of China Universities of posts and telecommunications 2002年第3期9卷 43-46页

作者： KONG Ling shan, YOU Meng,\ DING Wei (beijing university of posts and{3., beijing 100876, P. R. China) beijing university of posts and{3. Beijing 100876 P. R. China

In classical IPOA, the communication of two users between local AsynchronousTransfer Mode (ATM) ports needs a VCC, however, it is not an elegant solution to the ATM accessequipments design when the performance of the whole system is considered. Thus, we investigate theway to provide the improved IPOA protocol that uses switching way in local ports. And it is fullycompatible with the CIPOA by using the same protocol for ARP and IP forwarding. In addition, we alsopresent the design of one 10/100 Mbit/s auto adaptive IPOA client board with local switch abilityidea and CAM mechanism for our project.

关键词： ATM access network local switch mode (LSM) IPOA CAM

农村建设过程中信息化的战略、模式及文化意义

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China Communications 2009年第3期6卷 47-51页

作者：黄卉北京邮电大学经济与管理学院北京100871

本文从当今中国农村信息化现状入手,介绍了我国农村信息化的发展战略及战略措施,并分析了国内外农村信息化发展的主要模式,说明了在我国农村建设中信息化的重要意义。

关键词：农村信息化战略模式文化意义

A NOVEL SUPER-RESOLUTION BEAMFORMING ALGORITHM

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Journal of Electronics(China) 2007年第3期24卷 406-411页

作者： Guo Li Guo Yan Li Ning school of Information Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Institute of science PLA University of Science and Technology Nanjing 210007 China

A novel simply-structured hybrid smart antenna system suitable to be used in ad-hoc network terminals is proposed in this letter. The super-resolution beamforming algorithm is also pre-sented based on the system using DOA estimation results. The algorithm can switch the beamforming to the direction of the expected signal and get the best transmitting performance after the pre-beamforming of the Butler matrix. The shifting value formulas are presented to obtain the best SNR when there is no interfering signal and to acquire the highest Signal to Interference Ratio (SIR) as there is one interfering signal. When there are more than one interfering signals,the pre-beamforming feature of the Butler matrix can also suppress the interfering signals. Simulation results verified the algorithm.

关键词： Smart antennas Beamforming Direction-Of-Arrival (DOA) Iteration method

On Timing Offset Estimation of OFDM

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The Journal of China Universities of posts and telecommunications 2003年第1期10卷 39-43页

作者： XIAO Jian-hua, ZHANG Ping (Wireless Innovation Lab, beijing university of posts and telecommunications, beijing 100876, P.R. China) Wireless Innovation Lab Beijing University of Posts and Telecommunications 北京 100876

In this paper, a new timing offset estimation method for Orthogonal FrequencyDivision Multiplexing ( OFDM) systems are presented. Upon the receipt of just one trainingsequence, this presence of a signal and the start of the frame can be detected. The performances ofthe timing estimator in additive white Gaussian noise and the mo bile multipath channel areevaluated by simulation . The results delivered by this algorithm are compared with thosedelivered by Schmidl and Cox.

关键词： OFDM timing recovery InterSymbol interference (ISI) mobile multipathchannel