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User Identification Detector Based on Power of R Technique

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The Journal of china Universities of Posts and Telecommunications 2005年第4期12卷 66-69页

作者： WANG Chun-jiang YU Quan LIU Yuan-an Chinese Electronic Equipment System Engineering Company Beijing 100039 P.R. China Beijing Univesily of Posts and Telecommunications Beijing 100876 P.R. China

To avoid the inaccurate estimation of the active user＇ s number and the corresponding performance degradation, a novel POR-based User Identification Detector （UID） is proposed for the Code Division Multiple Acces （CDMA） systems. The new detector adopts the Power of R （POR） technique and the Multiple Signal Classification （MUSIC） method, which does not require the estimation of active users＇ number, and obtains lower false alarm probability than the subspace-based UID in the multipath channels. However, from our analysis, increasing the order m does not improve the performance. Therefore, when m is one, the performance of the new detector is maximal.

关键词： Power of R UID MUSIC CDMA near-far resistant

A Simulation Study on Channel Estimation for MIMO-OFDM Based Beyond 3G Mobile Systems

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The Journal of china Universities of Posts and Telecommunications 2005年第3期12卷 7-11页

作者： YIN Chang-chuan ZHAO Xue-yuan HOU Xiao-lin YUE Guang-xin School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

Multi-Input Multi-Output antennas based Orthogonal Frequency-Division Multiplexing （MIMO-OFDM） has been chosen as the air interface technology for china＇s beyond 3G Time-Division Duplex （TDD） mobile system in the FUTURE research project. Channel estimation plays a key role on the performance of the MIMO-OFDM receiver. In this paper, we present five channel estimation algorithms and study their performance in a simulated beyond 3G TDD mobile system, Simulation results show that the adaptive 2D-LMS algorithm we proposed recently has the best performance when the signal to noise ratio is lower than 8 dB.

关键词： OFDM channel estimation mobile communication beyond 3G

A Novel Medium Access Control for Ad hoc Networks Based on OFDM System

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The Journal of china Universities of Posts and Telecommunications 2005年第2期12卷 6-12页

作者： YU Yi-fan YIN Chang-chuan YUE Guang-xin School of Telecommunications Engineering Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

Recently, hosts of Medium Access Control （MAC） protocols for Ad hoc radio networks have been proposed to solve the hidden terminal problem and exposed terminal problem. However most of them take into no account the interactions between physical （PHY） system and MAC protocol. Therefore, the current MAC protocols are either inefficient in the networks with mobile nodes and fading channel or difficult in hardware implementation. In this paper, we present a novel media access control for Ad hoc networks that integrates a media access control protocol termed as Dual Busy Tone Multiple Access （DBTMA） into Orthagonal Frequency Division Multiplexing （ OFDM ） system proposed in IEEE 802.11 a standard. The analysis presented in the paper indicates that the proposed MAC scheme achieves performance improvement over IEEE 802.11 protocol about 25% -80% especially in the environment with high mobility and deep fading. The complexity of the proposed scheme is also lower than other implementation of similar busy tone solution. Furthermore, it is compatible with IEEE 802. 11a networks.

关键词： DBTMA OFDM medium access control 802. lla Ad hoc

A Limited Deflection Routing Algorithm Based on Burst Loss Threshold in OBS Networks

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The Journal of china Universities of Posts and Telecommunications 2005年第3期12卷 44-48页

作者： WANG Ru- yan LONG Ke-ping WU Wei YANG Xiao-long ZHU Wei-le The College of Electronic Engineering University of Electronic Science and Technology of China Chengdu 610054 P. R China Special Research Centre for Optical Internet & Wireless Information Networks Chongqing Univ of Posts and Telecom Chongqing 400065 P.R. China

The deflection routing protocol is an effective contention resolution in Optical Burst Switching network, However, it can worsen loss performance of non-deflected burst on the deflection route. To improve the burst loss performance, a limited deflection routing scheme based on burst loss threshold is proposed to prevent injudicious deflection routing. By using threshold check function, it restrainedly allows the deflected burst to preemptive network resource, consequently, improve the QoS performance of non-deflected burst. Simulation results show that the scheme can efficiently prevent deflected burst contending with non-deflected burst on deflection route, and effectively improve the burst loss performance of entire networks.

关键词： optical burst switching deflection routing algorithm burst loss threshold threshold check function

Experimental study on an all-optical switching based on MF-NOLM

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Optoelectronics Letters 2006年第3期2卷 172-174页

作者： SONG Xue-peng REN Xiao-min ZHANG Xia YANG Guang-qiang HUANG Yong-qing Beijing Univ. of Posts ＆ Telecom . Beijing China 700876 China

In this paper,the experiment on an all-optical switching is reported based on a microstructure fiber（MF）- nonlinear optical loop mirror（NOLM）. In the experiment, a 25-meter-long MF（ γ = 36W^-1 km^-1@ 1 550 nm） is used as a nonlinear medium of the nonlinear optical loop mirror and the input signal is generated by a 10 GHz tunable picosecond laser source,with a full-width at half-maximum （FWHM） of 2 ps and centered at 1 550 nm. With the increase of input power,a π nonlinear phase shift is obtained by a 40/60 coupler in the experiment,but the same result can not be found by a 48/52 coupler. Additionally,the switching devices can also be used as an all-optical regeneration.

关键词： MFNOLM 光子交换微观结构光纤

分布式天线系统中选择合并的衰落统计分析(英文)

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山东大学学报（工学版） 2007年第5期37卷 83-88页

作者：李政王晓东卜智勇海军航空工程学院电子工程系山东烟台264001 海军潜艇学院航海观通系山东青岛266071 上海无线通信研究中心上海200050

对于采用选择合并方案的分布式天线系统,当各分集支路经受独立且不等同分布的复合衰落时,分析了系统合并输出包络的平均电平交叉率和平均衰落持续时间,得到这些二阶统计量的精确表达式.该方法对于任意分集支路数目下的Rayleigh-lognorma... 详细信息

对于采用选择合并方案的分布式天线系统,当各分集支路经受独立且不等同分布的复合衰落时,分析了系统合并输出包络的平均电平交叉率和平均衰落持续时间,得到这些二阶统计量的精确表达式.该方法对于任意分集支路数目下的Rayleigh-lognormal,Ricean-lognormal和Nakagami-lognormal三种复合衰落环境均是有效的.仿真结果验证了所得表达式的正确性.

关键词：分布式天线系统复合衰落信道选择分集平均电平交叉率平均衰落持续时间

CDMA时分模式下的统计贝叶斯信道估计(英文)

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重庆邮电大学学报（自然科学版） 2007年第4期19卷 458-460页

作者：沈壁川申敏郑建宏重庆重邮信科股份有限公司重庆400065

分析了CDMA时分模式下的统计贝叶斯信道估计。通过理论分析得到了简化的贝叶斯信道估计权值,其等同将后向概率的最大化。提出了一种综合贝叶斯估计和门限的改进方法。计算机仿真结果表明不仅提高了信道估计精度,而且保持了较低的计算复... 详细信息

分析了CDMA时分模式下的统计贝叶斯信道估计。通过理论分析得到了简化的贝叶斯信道估计权值,其等同将后向概率的最大化。提出了一种综合贝叶斯估计和门限的改进方法。计算机仿真结果表明不仅提高了信道估计精度,而且保持了较低的计算复杂度。

关键词：码分多址贝叶斯信道估计联合检测加权系数