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An improved dynamic user equipment power saving mechanism for LTE system and performance analysis

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Science china(Information Sciences) 2010年第10期53卷 2075-2086页

作者： XU HaiBo, tian hui , HUANG Bo & zhang ping key laboratory of universal wireless communications, ministry of education {3. university of Posts and telecommunications, beijing 100876, china 1. key laboratory of universal {3. communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In order to minimize the power consumption of user equipments (UEs), and further to support various services and transmissions of large amount of data, the power saving mechanisms have been investigated for most remarkable wireless systems. In this paper, an improved dynamic discontinuous reception (D-DRX) scheme is presented for LTE system, which is able to adaptively adjust the inactivity timer and the sleep period of UEs’ receivers. Moreover, theoretical analysis based on the Markov chain is provided for the D-DRX scheme. Several numerical examples quantitatively show that the D-DRX scheme can capture various packet arrival patterns and scheduling behaviors of system to make a better tradeoff between power saving and packet delay by considering the length of packet queue.

关键词： power saving DRX Markov chain LTE-advanced

Emergency access mechanism in IEEE 802.15.4 for wireless body area sensor networks

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The Journal of china Universities of Posts and telecommunications 2009年第6期16卷 24-31页

作者： GUO Yan-yan,KANG Gui-xia,CAO Yu,zhang ping key laboratory of universal wireless communications,ministry of education,beijing {3. of Posts and telecommunications,beijing 100876,china [a] key laboratory of universal {3. communications ministry of education beijing university of Posts and telecommunications beijing 100876 china

IEEE 802.15.4 protocol has attracted much attention in research and industrial communities as candidate technology for wireless body area sensor networks（WBASNs）.IEEE 802.15.4 supports the exclusive use of a wireless channel through guaranteed time slot（GTS）.However,on one hand,bandwidth underutilization rate may be lower because of the variance between the guaranteed bandwidth and the arrival *** the other hand,the waiting time for transmitting emergency notification is getting longer when the GTSs assigned to the nodes increase in *** solve these problems,in this article,a new scheme is proposed to reduce transmission delay for the alarm notification in emergent *** results are presented to validate the efficiency of the proposed scheme by comparing it with the medium access control（MAC） protocol of IEEE 802.15.4.

关键词： WBASN GTS IEEE 802.15.4 emergency mechanism

Novel resource allocation algorithms for multiuser downlink MIMO-OFDMA of FuTURE B3. systems

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Progress in Natural Science:Materials International 2009年第9期19卷 1141-1146页

作者： qiaoyun sun, {3. tian *, Shuang Wang, kun dong, ping zhang key laboratory of universal wireless Communication, {13., wireless Technology Innovation Institute, beijing university of Posts & telecommunications, beijing 100876, china [a]key laboratory of universal {3. Communication Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts & Telecommunications Beijing 100876 China

In this paper, subcarrier and power allocation problems for multiuser downlink MIMO-OFDMA of the FuTURE B3. TDD system are investigated. For the reciprocity of the TDD channel, the channel state information can be employed at the transmitter, thus eigen beamforming can be implemented efficiently. With the goal of minimizing the total transmit power under the condition that the QoS requirement of each user can be guaranteed, a novel dynamic resource allocation scheme is proposed to exploit the multiuser diversity gain. The proposed algorithm involves adaptive subcarrier allocation, adaptive modulation and eigen beamforming and achieves significant improvement in overall system performance. Based on the proposed scheme, a modified bit and power allocation is developed. The modified scheme reduces the computational complexity at little expense of system performance. Numerical simulations show that the proposed algorithm and the modified scheme can decrease the total transmit power effectively.

关键词： Adaptive modulation and coding Dynamic resource allocation Eigen beamforming MIMO–OFDMA

Experimental investigation of MIMO relay channels statistics and capacity based on wideband outdoor measurements at 2.3. GHz

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Science china(Information Sciences) 2011年第9期54卷 1945-1956页

作者： NIE Xin 1,2,zhang JianHua 1,2,LIU ZeMin 1 & zhang ping 1,2 1 {3. laboratory of universal wireless communications,ministry of education beijing university of Posts and telecommunications,beijing 100876,{13. 2 wireless Technology Innovation Institute,beijing university of Posts and telecommunications,beijing 100876,{13. 1. key laboratory of universal {3. communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

Relay,which serves to enhance the performance of future communication networks,is one of the most promising techniques for IMT-Advanced *** potential performance improvement of relay is investigated in this *** investigation consists of two *** the first step,to obtain a better understanding of the fundamental properties of relay channels,we conducted outdoor measurements at 2.3. GHz with 50 MHz bandwidth in a typical urban area of *** links constituting the relay transmission,i.e.,the link between base station and relay station,the link between relay station and mobile station and the link between base station and mobile station were measured by employing a real-time channel *** main factors that affect the MIMO channel capacity,i.e.,the channel gain and effective degrees of freedom,are *** cross-polarization discrimination was obtained by utilizing space-alternating generalized expectation-maximization *** channel parameters of the three links are statistically analyzed and *** the second step,based on the measured data,the performance of different relaying schemes,i.e.,amplify-and-forward and decode-and-forward,is *** impact of RS antenna configuration on the capacity is also *** measurement and evaluation results reveal that the relay can significantly improve the system coverage and performance.

关键词： MIMO relay channels IMT-Advanced frequency band channel characteristics relay performance evaluation

EXIT analysis of M-algorithm based MIMO detectors and LDPC code design optimization

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Science in china(Series F) 2009年第12期52卷 2248-2258页

作者： YOU MingHou1,2, TAO XiaoFeng1,2, CUI QiMei1,2 & zhang ping1,2 1 wireless Technology Innovation Institute, {3. university of Posts and telecommunications, beijing 100876, china 2 key laboratory of universal wireless communications, ({3. university of Posts and telecommunications), ministry of education, beijing 100876, china wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China key laboratory of universal {3. communications (Beijing University of Posts and Telecommunications) Ministry of Education Beijing 100876 China

This paper investigates joint design and optimization of both low density parity check （LDPC） codes and M-algorithm based detectors including iterative tree search （ITS） and soft-output M-algorithm （SOMA） in multiple-input multiple-output （MIMO） systems via the tool of extrinsic information transfer （EXIT） charts. First, we present EXIT analysis for ITS and SOMA. We indicate that the extrinsic information transfer curves of ITS obtained by Monte Carlo simulations based on output log-likelihood rations are not true EXIT curves, and the explanation for such a phenomenon is given, while for SOMA, the true EXIT curves can be computed, enabling the code design. Then, we propose a new design rule and method for LDPC code degree profile optimization in MIMO systems. The algorithm can make the EXIT curves of the inner decoder and outer decoder match each other properly, and can easily attain the desired code with the target rate. Also, it can transform the optimization problem into a linear one, which is computationally simple. The significance of the proposed optimization approach is validated by the simulation results that the optimized codes perform much better than standard non-optimized ones when used together with SOMA detector.

关键词： MIMO systems iterative receiver LDPC codes code optimization EXIT charts M-algorithm

A survey on the network models applied in the industrial network optimization

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Science china(Information Sciences) 2024年第2期67卷 85-103页

作者： Chao dong Xiaoxiong XIONG Qiulin XUE Zhengzhen zhang Kai NIU ping zhang key laboratory of universal {3. communications Ministry of EducationBeijing University of Posts and Telecommunications Smart City College Beijing Union University

Network architecture design is critical for optimizing industrial networks. Network architectures can be classified into small-scale networks and large-scale networks based on scale. Graph theory is an efficient mathematical tool for network topology modeling. For small-scale networks, their structure often has regular topology. For large-scale ones, the current body of work mainly focuses on random characteristics of network nodes and edges. Recently, widely used models include random networks, small-world networks,and scale-free networks. In this study, starting from the scale of the network, network modeling methods based on graph theory as well as their industrial applications, are summarized and analyzed. Moreover, a novel network performance metric, called system entropy, is proposed. From the perspective of mathematical properties, an analysis of its non-negativity and concavity is performed. The advantage of system entropy is that it can cover the existing regular networks, random networks, small-world networks, and scale-free networks, and has strong generality. The simulation results reveal that this proposed metric can achieve the comparison of various industrial networks under different models.

关键词： industrial network small-scale network large-scale network graph theory system entropy

In the development of wireless cognitive science

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Chinese Science Bulletin 2012年第28期57卷 3661-3661页

作者： zhang ping key laboratory of universal wireless communications of ministry of education, beijing {3. of Posts and telecommunications, beijing 100876, china beijing Univ Posts & Telecommun Minist Educ Key Lab Universal Wireless Commun Beijing 100876 Peoples R China

Recently,driven by the technology innovations and application requirements,wireless network technologies developed rapidly with high data rate and wide system bandwidth,which have already changed the way that people u... 详细信息

关键词：无线网络技术认知科学无线电频谱无线接入技术异构网络高数据速率高频谱效率技术创新

A LOW-COMPLEXITY PORT SELECTION AND POWER ALLOCATION SCHEME IN DISTRIBUTION MIMO SYSTEMS

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Journal of Electronics(china) 2010年第2期27卷 145-150页

作者： zhang Ningbo Kang Guixia Guo Yanyan zhang ping beijing university of Posts and telecommunications Key Laboratory of Universal Wireless Communications Ministry of Education Beijing 100876 P. R. China

Information theoretical results have shown that Distributed Antenna Systems (DAS) can obtain higher capacity than Co-located Antenna Systems (CAS). In this paper,we investigate a downlink port selection and power allocation scheme in Distributed Multiple-Input Multiple-Output (D-MIMO) systems,where Distributed Antenna (DA) ports randomly locate in the cell. The contri-bution of this paper can be summarized as two parts. Firstly,we analyze how antenna correlation af-fects power allocation in D-MIMO systems. Secondly,based on large scale fading and antenna corre-lation,a low-complexity port selection and power allocation scheme is proposed. In the proposed scheme,we take both large scale fading and antenna correlation into consideration. Moreover,User Equipment (UE) only needs to feedback the rank of transmit antenna correlation matrix,which will not increase system complexity too much. Simulation results verify the capacity improvement based on the proposed power allocation scheme.

关键词： Large scale fading Antenna correlation Port selection Power allocation

Reconfiguration decision making in cognitive wireless network

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Science Bulletin 2012年第Z2期 3713-3722页

作者： zhang ping,HE Qian,FENG ZhiYong * & zhang QiXun {3. Technology Innovation Institute(WTI),key laboratory of universal {3. communications of ministry of education,beijing university of Posts and telecommunications,{13.,china

Facing the challenges of dynamic adaptation capabilities in the time-varying environment of cognitive wireless networks(CWNs),we introduce reconfiguration capabilities that flexibly and dynamically adapt to changing wireless environments and service *** an essential characteristic of CWNs,the cognitive reconfiguration can meet user requirements,realize interoperability between heterogeneous networks,make full use of radio resources and adapt to time-varying environments to achieve end-to-end ***,the reconfiguration implementation is still challenging due to the need for complex environment cognition,multi-objective optimization,autonomic decision-making and end-to-end requirement *** an intelligent technology for solving complex issues,we apply adaptive neuro-fuzzy inference system(ANFIS) techniques in this paper to address these challenges in cognitive reconfiguration for self-learning and optimal decision making based on multi-domain cognition ***,this paper designs a generic ANFIS cognitive reconfiguration system including three functional entities,which are the context management module,multi-domain database and ANFIS optimization ***,numerous results prove the effective performance improvements of the ANFIS based reconfiguration solution in CWN for global end-to-end goals.

关键词： cognitive reconfiguration cognitive wireless network adaptive neuro-fuzzy inference system