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Cross-Layer Framework for Capacity Analysis in Multiuser ultra-dense Networks with Cell DTx

China Communications 2019年第9期16卷 106-121页

作者： Qing Li Yu Chen Qimei Cui Yu Gu Guoqiang Mao National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computing and Communications University of Technology SydneyNSW 2007Australia

Cell discontinuous transmission(Cell DTx)is a key technology to mitigate inter-cell interference(ICI)in ultra-dense networks(UDNs).The aim of this work is to understand the impact of Cell DTx on physical-layer sum rates of SBSs and link-layer quality-of-service(QoS)performance in multiuser UDNs.In this work,we develop a cross-layer framework for capacity analysis in multiuser UDNs with Cell DTx.In particular,we first extend the traditional one-dimensional effective capacity model to a new multidimensional effective capacity model to derive the sum rate and the effective capacity.Moreover,we propose a new iterative bisection search algorithm that is capable of approximating QoS performance.The convergence of this new algorithm to a unique QoS exponent vector is later proved.Finally,we apply this framework to the round-robin and the max-C/I scheduling policies.Simulation results show that our framework is accurate in approximating 1)queue length distribution,2)delay distribution and 3)sum rates under the above two scheduling policies,and further show that with the Cell DTx,systems have approximately 30% higher sum rate and 35% smaller average delay than those in full-buffer scenarios.

关键词： effective capacity QoS performance sum rates multiuser scheduling ultra-dense network (UDN)

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Inter-Operator Interference Coordination for CoPrimary Spectrum Sharing in UDN

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China Communications 2015年第S1期12卷 104-112页

作者： YU Qiaoling WANG Jiang YANG Xiumei ZHU Yuanping TENG Yong Horneman Kari Shanghai Research Center for Wireless Communications Shanghai Institute of Microsystem and Information Technology (SIMIT) Chinese Academy of Sciences (CAS) Nokia

Co-primary spectrum sharing for multiple operators has been utilized to fully explore the spectrum resources and thus improve the spectrum efficiency. The inter-operator interference(IOI) problem should be seriously considered in order to achieve the mentioned target, especially under the scenario of the ultradense network(UDN) in the fifth generation(5G) wireless systems. To solve this problem, we propose an asymmetrical power levels based soft IOI coordination mechanism. The shared spectrum pool is consisted of three separated parts, where each part can be dynamically adjusted according to the minimal spectrum demand from each operator. Furthermore, different power masks are configured to different parts for each operator. The simulation results show that the proposed mechanism can improve the network spectrum efficiency significantly.

关键词： ultra-dense network inter-operator interference coordination co-primary spectrum sharing

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Transmitter-Receiver Path Selection for Cell Range Extension Using Multi-Hop D2D

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Computers, Materials & Continua 2021年第8期68卷 2075-2093页

作者： Farah Akif Kiran Sultan Aqdas N.Malik Ijaz M.Qureshi Saba Mahmood Department of Electrical Engineering International Islamic UniversityIslamabad44000Pakistan Department of CIT FASKing Abdulaziz UniversityJeddah21551Saudi Arabia Department of Electrical Engineering Air UniversityIslamabad44000Pakistan Department of Computer Science Bahria UniversityIslamabad44000Pakistan

Conventional approach of dealing with more users per coverage area in cellular networks implies densifying the amount of(Access Point)AP which will eventually result in a larger carbon footprint.In this paper,we propose a base station off-loading and cell range extension(CRE)scheme based on multi-hop device-to-device(MHD2D)path selection between transmitter and receiver node.The paper also provides derivations of upper and lower bounds for energy efficiency,capacity,and transmit power.The proposed path selection scheme is inspired by the foraging behavior of honey bees.We present the algorithm as a modified variant of the artificial bee colony algorithm(MVABC).The proposed optimization problem is modeled as a minimization problem where we optimize the Energy Efficiency(EE).The proposed path selection MVABC is compared with the Genetic Algorithm(GA)and also with classical artificial bee colony(ABC)through simulations and statistical analysis.The student’s t-test,p-value,and standard error of means(SEM)clearly show that MVABC based path selection out-performs the GA and classical ABC schemes.MVABC based approach is 66%more efficient when compared with classic ABC and about 62%efficient when compared with GA based scheme.

关键词： Multi-hop ultra-dense D2D path-selection ABC GA

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Power optimization for multiple QoS,delay,and BER classes relying on nite-delay information theory

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Journal of Communications and Information Networks 2017年第1期2卷 33-40页

作者： Chen Gong Qian Gao Lajos Hanzo Zhengyuan Xu Key Laboratory of Wireless-Optical Communications Chinese Academy of SciencesSchool of Information Science and TechnologyUniversity of Science and Technology of ChinaHefei 230027China Shenzhen Graduate School Tsinghua UniversityShenzhen 518055China School of Electronics and Computer Science University of SouthamptonSouthamptonSO171BJU.K.

Future communication systems will include di erent types of messages requiring di erent transmission rates,packet lengths,and service qualities.We address the power-optimization issues of communication systems conveying multiple message types based on nite-delay information theory.Given both the normalized transmission rate and the packet length of a system,the actual residual decoding error rate is a function of the transmission power.We propose a generalized power allocation framework for multiple message types.Two di erent optimization cost functions are adopted:the number of service-quality violations encountered and the sum log ratio of the residual decoding error rate.We provide the optimal analytical solution for the former cost function and a heuristic solution based on a genetic algorithm for the latter one.Finally,the performance of the proposed solutions are evaluated numerically.

关键词： 5G communication short packet ultra-dense delay-limited nite-length information theory power optimization

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Growing a Kerr Black Hole

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Journal of Modern Physics 2015年第13期6卷 1789-1792页

作者： Leon F. Phillips University of Canterbury Christchurch New Zealand

Growth of a black hole requires the participation of a near-by accretion disk if it is to occur at a significant rate. The Kerr solution of Einstein’s equation is a vacuum solution, but the center of a realistic Kerr black hole is not a vacuum, so the predicted disk singularity does not exist. Instead, the center of a black hole is occupied by an ultra-dense, spheroidal core whose diameter is greater than that of the theoretical disk singularity. The surface of a black hole’s core is continually bombarded by energetic particles from the external universe. Hence the cold remnant of a gravitationally-collapsed star that has often been assumed to be present at the center of a black hole must be replaced conceptually by a quark-gluon plasma whose temperature is of the order of 1012 K or more. The gravitational potential well of a black hole is extremely deep (TeV), but the number of discrete energy levels below the infinite-red-shift surface is finite. Information can be conveyed to observers in the external universe by thermally-excited fermions that escape from levels near the top of a black hole potential well.

关键词： Kerr Black Hole No Singularity ultra-dense Core Deep (Teravolts) Potential Well High-Energy Incoming Particles Quark-Gluon Plasma Information Flow through Event Horizon

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