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101.
Sangchoon Kim 《ETRI Journal》2011,33(6):949-952
In this letter, a simplified suboptimum receiver based on soft‐limiting for the detection of binary antipodal signals in non‐Gaussian noise modeled as a generalized normal‐Laplace (GNL) distribution combined with Gaussian noise is presented. The suboptimum receiver has low computational complexity. Furthermore, when the number of diversity branches is small, its performance is very close to that of the Neyman‐Pearson optimum receiver based on the probability density function obtained by the Fourier inversion of the characteristic function of the GNL‐plus‐Gaussian distribution. 相似文献
102.
电信运营商业务支撑系统投资巨大,在项目可行性研究阶段使用合理方法精确估算投资显得非常重要.本文分析了现有投资估算存在的问题,通过对历史数据进行统计分析,提出了优化思路. 相似文献
103.
TD-SCDMA集群小区使用宏分集技术可以有效的克服大尺度衰落,保证信号质量。本文首先分析了在没有任何措施的前提下进行宏分集组网,但前向容量会随着宏分集基站数的增多而减少。在分析容量损失原因的基础上,我们进一步提出在终端利用Rake接收机对各路信号进行同步、相位调整,再进行最大比值合并,然后发送给用户,由此,前向容量大大提高。 相似文献
104.
6 dBm at 2.2 GHz, and a gain of 18.8 dB and IIP3 of 7.3 dBm at 4.5 GHz. The whole front-end consumes 12 mA current at 1.2 V voltage supply for the LNA and 2.1 mA current at 1.8 V for the mixer, with a die area of 1.2 × 1 mm2. 相似文献
105.
MATLAB是一种高度集成的计算机语言,具有强大的科学计算功能及灵活的程序设计流程。文中充分利用MATLAB的优势,通过非线性回归分析函数nlinfit建立了两个非线性回归模型,对我国高职院校的生均成本进行了一些研究。 相似文献
106.
107.
108.
从非法信号攻击卫星转发器的原理入手,探讨了有线电视前端卫星信号安全接收的措施,对保证有线电视的安全播出具有重要的参考意义。 相似文献
109.
Hierarchical Mobile IPv6 (HMIPv6) is an enhanced version of Mobile IPv6 designed to reduce signaling overhead and to support
seamless handoff in IP-based wireless/mobile networks. To support more scalable services, HMIPv6 networks can be organized
as the form of a multi-level hierarchy architecture (i.e., tree structure). However, since multi-level HMIPv6 networks incur
additional packet processing overhead at multiple mobility agents, it is important to find the optimal hierarchy level to
minimize the total cost, which consists of the location update cost and the packet delivery cost. In this paper, we investigate
this problem, namely the design of an optimal multi-level HMIPv6 (OM-HMIPv6) network. To accomplish this, we design a function
to represent the location update cost and the packet delivery cost in multi-level HMIPv6 networks. Based on these formulated
cost functions, we calculate the optimal hierarchy level in multi-level HMIPv6 networks, in order to minimize the total cost.
In addition, we investigate the effects of the session-to-mobility ratio (SMR) on the total cost and the optimal hierarchy.
The numerical results, which show various relationships among the network size, optimal hierarchy, and SMR, can be utilized
to design an optimal HMIPv6 network. In addition, the analytical results are validated by comprehensive simulations.
Sangheon Pack received his B.S. (2000, magna cum laude) and Ph.D. (2005) degrees from Seoul National University, both in computer engineering.
He is a post doctor fellow in the School of Computer Science and Engineering at the Seoul National University, Korea. He is
a member of the IEEE and ACM. During 2002–2005, he was a recipient of the Korea Foundation for Advanced Studies (KFAS) Computer
Science and Information Technology Scholarship. He has been also a member of Samsung Frontier Membership (SFM) from 1999.
He received a student travel grant award for the IFIP Personal Wireless Conference (PWC) 2003. He was a visiting researcher
to Fraunhofer FOKUS, German in 2003. His research interests include mobility management, wireless multimedia transmission,
and QoS provision issues in the next-generation wireless/mobile networks.
Yanghee Choi received B.S. in electronics engineering from Seoul National University, M.S. in electrical engineering from Korea advanced
Institute of Science, and Doctor of Engineering in Computer Science from Ecole Nationale Superieure des Telecommunications
(ENST) in Paris, in 1975, 1977 and 1984 respectively. Before joining the School of Computer Engineering, Seoul National University
in 1991, he has been with Electronics and Telecommunications Research Institute (ETRI) during 1977–1991, where he served as
director of Data Communication Section, and Protocol Engineering Center. He was research student at Centre National d'Etude
des Telecommunications (CNET), Issy-les-Moulineaux, during 1981–1984. He was also Visiting Scientist to IBM T.J. Watson Research
Center for the year 1988–1989. He is now leading the Multimedia Communications Laboratory in Seoul National University. He
is also director of Computer Network Research Center in Institute of Computer Technology (ICT). He was editor-in-chief of
Korea Information Science Society journals. He was chairman of the Special Interest Group on Information Networking. He has
been associate dean of research affairs at Seoul National University. He was president of Open Systems and Internet Association
of Korea. His research interest lies in the field of multimedia systems and high-speed networking.
Minji Nam received her B.S. and M.S degrees in Computer Science and Engineering from Seoul National University in 2003 and 2005, respectively.
From 2005, she has worked on Portable Internet Development Team for Korea Telecom. Her research interests are mobile networks,
portable internet technology (IEEE 802.16) and Mobile IPv6. 相似文献
110.
User Independent Paging Scheme for Mobile IP 总被引:1,自引:0,他引:1
Jiang Xie 《Wireless Networks》2006,12(2):145-158
Multi-step paging has been widely proposed in personal communications services (PCS) systems to reduce the signaling overheads.
Similar ideas can be applied to Mobile IP to provide IP paging services. However, current proposed multi-step paging schemes
are user dependent under which the partition of paging areas and the selection of paging sequence are different for each user.
The performance of a user dependent paging scheme for individual users may be affected by many factors. It is often difficult
to achieve perfect performance for each user. In addition, when multiple users are paged at the same time, user dependent
paging schemes may consume significant system resources. This paper introduces a user independent paging scheme where the
paging criterion is not based on individual user information. The goal of user independent paging is to provide satisfactory
overall performance of the whole system, when personalized optimal performance for each user is hard to obtain. The user independent
paging scheme is proposed for IP mobility for its easy implementation and convenient combination with paging request aggregation.
The paging criterion adopted is the mobility rate of each subnet determined by the aggregated movements of all mobile users.
In order to implement the proposed scheme, a concept of “semi-idle state” is introduced and the detailed solution for obtaining
mobility rate is presented. Analytical results show that when paging one user at a time, the performance of the proposed user
independent paging scheme is comparable to that of the paging schemes based on perfect knowledge of user movement statistics.
When paging multiple users simultaneously and when the knowledge on individual user behavior is not perfectly accurate, the
proposed scheme has remarkable advantages in terms of reducing the overall paging cost.
Jiang Xie received her B.E. degree from Tsinghua University, Beijing, China, in 1997, M.Phil. degree from Hong Kong University of Science
and Technology in 1999, and M.S. and Ph.D. degrees from Georgia Institute of Technology in 2002 and 2004, respectively, all
in electrical engineering. She is currently an assistant professor with the Department of Electrical and Computer Engineering
at the University of North Carolina-Charlotte. Her current research interests include resource and mobility management of
wireless networks,QoS provisioning, and next-generation Internet. She is a member of IEEE and ACM. 相似文献