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Resource allocation based on genetic algorithm for multi-hop OFDM system with non-regenerative relaying

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The Journal of China Universities of posts and telecommunications 2009年第5期16卷 25-32页

作者： SHI Jie , XU Wen-jun, HE Zhi-qiang, NIU Kai, WU Wei-ling school of Information and Telecommunication Engineering, beijing university of posts and telecommunications, beijing 100876, China [a]school of Information and Telecommunication Engineering beijing university of posts and telecommunications beijing 100876 China

This article investigates resource allocation in multi-hop orthogonal frequency division multiplexing （OFDM） system with amplifying-and-forwarding relaying to maximize the end-to-end capacity, Most existing methods for multi-hop system focus on power allocation or subcarrier selection separately, but joint resource allocation is rarely considered due to the absence of effective interaction schemes. In this work, a novel joint resource allocation methodology is proposed based on Partheno genetic algorithm （PGA）, which produces excellent subcarrier allocation set （referred to as individual in PGA） with higher capacity by evolution operator generation by generation. In addition, an adaptive power allocation is also designed to evaluate the fitness of PGA and further enhance the system capacity. Both theoretical analysis and simulated results show the effectiveness of the proposed joint strategy. It outperforms the traditional method by as much as 4.% capacity improvement for 3-hop relaying system when system power is high, and obtains much more capacity enhancement percent under conditions of low system power.

关键词： multi-hop OFDM system non-regenerative relaying genetic algorithm power allocation subcarrier selection resource allocation

Performance analysis of rate-adaptive cooperative MAC based on wireless local area networks

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The Journal of China Universities of posts and telecommunications 2009年第5期16卷 78-85页

作者： ZHANG Yang , XU Hong-kun, CHANG Yong-yu, YANG Da-cheng, WANG Ya-feng school of Information and Communication Engineering, beijing university of posts and telecommunications, beijing 100876, China [a]school of Information and Communication Engineering beijing university of posts and telecommunications beijing 100876 China

Bi-dimensional Markov chain model based on cooperative medium access control （MAC） of wireless local area networks （WLAN） is considered to reflect system performance accurately. Two basic factors that affect the analysis results are station retry limits and non-saturated transmit probability. A uniform solution considering both factors is proposed. To prove the theoretical analysis, a cooperative MAC （CoopMAC） topology is established and the simulation model is enhanced by changing the cooperative table to the nodes＇ memory with more information added. Meanwhile, the three-way handshake scheme is modified and a handshake threshold is set based on the packet size. Simulation results show the performance analytical model is accurate, and the rate-adaptive cooperative MAC protocol significantly improves the network performance in terms of non-saturated system throughput and delay.

关键词： performance analysis cooperative MAC bi-dimensional Markov Chain non-saturated transmit station retry limit

Improved discriminative training for generative model

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The Journal of China Universities of posts and telecommunications 2009年第3期16卷 126-130页

作者： WU Ya-hui,GUO Jun,LIU Gang Laboratory of Pattern Recognition and Intelligent System,beijing university of posts and telecommunications,beijing 100876,China [a]Laboratory of Pattern Recognition and Intelligent System beijing university of posts and telecommunications beijing 100876 China

This article proposes a model combination method to enhance the discriminability of the generative model. Generative and discriminative models have different optimization objectives and have their own advantages and drawbacks. The method proposed in this article intends to strike a balance between the two models mentioned above. It extracts the discriminative parameter from the generative model and generates a new model based on a multi-model combination. The weight for combining is determined by the ratio of the inter-variance to the intra-variance of the classes. The higher the ratio is, the greater the weight is, and the more discriminative the model will be. Experiments on speech recognition demonstrate that the performance of the new model outperforms the model trained with the traditional generative method.

关键词： model combination discriminability generative model training speech recognition

Hopping control channel MAC protocol for opportunistic spectrum access networks

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The Journal of China Universities of posts and telecommunications 2010年第6期17卷 65-71页

作者： FU Jing-tuan,JI Hong,MAO Xu Key Laboratory of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,China [a] Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

关键词： channel hopping MAC protocol OSA Markov chain

Network parameters awareness for routing discovery in autonomic optical Internet

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The Journal of China Universities of posts and telecommunications 2009年第2期16卷 84-88,128页

作者： JIN Jin WANG Hong-xiang JI Yue-feng Key Laboratory of Optical Communication and Lightwave Technologies,beijing university of posts and telecommunications,beijing 100876,China [a]Key Laboratory of Optical Communication and Lightwave Technologies beijing university of posts and telecommunications beijing 100876 China

The article proposes a network parameter-awareness （NPA） method and applies it to routing discovery algorithms in autonomic optical Internet. This NPA method can perceive the main parameters of the network, such as delay, jitter and traffic, which can represent the current situation of the network. And these parameters enable network to determine the appropriate nodes for routing discovery. The simulation results of evaluating performance of a network with NPA method and its routing applications show that the method and its applications in routing improve the performance of the network significantly with quality of service （QoS） guaranteed.

关键词： NPA autonomic optical Internet self-aware muting QoS

On the Symmetry Classes of Functions

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Wuhan university Journal of Natural sciences 2005年第5期10卷 813-816页

作者： ZHU Ping~1,2, FAN Yun~3 1. school of Mathematics and Statistics, Wuhan university, Wuhan 4.0072, Hubei, China 2. school of science,{4., beijing 100876, China 3. school of Mathematics and Statistics, Huazhong Normal university, Wuhan 4.0079, Hubei, China Wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) beijing university of posts and telecommunications School of Science Beijing China (GRID:grid.31880.32) Huazhong Normal university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.411407.7) (ISNI:***)

Let R be an integral domain of characteristic zero such that the corresponding group rings have block decompositions. We first prove that the submodule consisting of all the R-valued ξi-symmetric functions of several variables is a symmetry class, where ξi is any block character. Then we present a relationship among certain operators introduced for block character. Then we present a relationship among certain operators introduced for block characters. As a consequence, we obtain a decomposition of an arbitrary R-valued function of several variables. Finally, we describe the symmetry property of such summands and determine all the symmetry classes.

关键词： symmetry class strict symmetry class blockcharacter ξi-symmetric function block idempotent

Robust L2-L∞ control for uncertain singular systems with time-varying delay

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Progress in Natural science:Materials International 2008年第8期18卷 1015-1021页

作者： Lin Lia,*, Yingmin Jiaa, Junping Dub, Shiying Yuan c a The Seventh Research Division, beijing university, beijing 100083, China b beijing Key Laboratory of Intelligent {4. Software and Multimedia, beijing university of posts and telecommunications, beijing 100876, China c school of Electrical Engineering and Automation, Henan Polytechnic university, Jiaozuo 4.4.00, China The Seventh Research Division Beijing University Beijing 100083 China beijing Key Laboratory of Intelligent telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing 100876 China school of Electrical Engineering and Automation Henan Polytechnic University Jiaozuo 454000 China

We study the problem of L2-L1 control for a class of uncertain singular systems with time-delay and norm-bounded parameter uncertainties in this paper. A new delay-dependent robust stability criterion is obtained in terms of linear matrix inequalities (LMIs). Based on this criterion, a state feedback controller is designed to guarantee that the closed-loop system is regular, impulse free and stable with a prescribed L2-L1 performance satisfied for all admissible parameter uncertainties. A simulation example is included to illustrate the effectiveness of the proposed method.

关键词： L2–L1 control Singular systems Delay-dependent condition LMIs

Error exponents for two-hop Gaussian multiple source-destination relay channels

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science China(Information sciences) 2012年第2期55卷 348-359页

作者： DENG PanLiang1,3,LIU YuanAn1,3,XIE Gang2,3,WANG XiaoYu1,3,TANG BiHua1,3 & SUN JianFeng1,3 1school of Electronic Engineering,beijing university of posts and {4.,beijing 100876,China 2school of Information and Communication Engineering,beijing university of posts and {4.,beijing 100876,China 3Key Laboratory of Universal Wireless Communication,Ministry of Education,beijing 100876,China 1. school of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Laboratory of Universal Wireless Communication Ministry of Education Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

We investigate the two-hop multiple source-destination relay channels using the rate splitting trans-mission scheme where each source can split its message into private and public *** determine the system error probability via integrated exponent function under amplify-and-forward(AF)and decode-and-forward(DF)relay *** most significant difference between AF and DF system error probability evaluations lies in a minimized cut-set bound of transmission rate under the DF *** are many cases among transmission rate intervals for different system parameters(*** power)and it is extremely complex to derive the system error probability for the DF *** obtain a relatively simple result,which unifies various cases by a few *** results show that the system error probability decreases with the increase of the public ***,in order to draw deep insight into the reliability requirement of each source node in this network,we provide the error exponent region(EER)for different source nodes to show the trade-off of error probability among source nodes.

关键词： error exponent error exponent region rate splitting multiple source-destination relay channel

Bandwidth allocation and admission control scheme based on Nash bargaining solution for WiMAX systems

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The Journal of China Universities of posts and telecommunications 2010年第2期17卷 53-58页

作者： CAI Dao-jin ,JI Hong,LI Xi Key Laboratory of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,China [a] Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

Development of fair and efficient bandwidth allocation and admission control schemes is one of the key issues in the design of IEEE 802.16 broadband wireless access systems in time division multiple access （TDMA） mode. In this article, the problem of bandwidth allocation and admission control is formulated as a Nash bargaining model. The nash bargaining solution （NBS） derived from the cooperative game is adopted to maximize the spectrum utilization. Analysis and simulation results show that there is a unique Pareto optimal bandwidth allocation solution by using NBS among various flows. Furthermore, maximum utility of the system can also be maintained by using the admission control policy with different number of connections and variable channel qualities. The total throughput of the proposed scheme is close to the maximal one, while significantly improving fairness compared to the existing solutions.

关键词： NBS game theory bandwidth allocation admission control IEEE 802.16