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全球移动通信技术的发展已厅三个阶段,当前的公众移动通信新技术层出不穷,新系统不断涌现。我国移动通信运营业增长非常迅猛,预计“九五”期间将有4千亿元的巨大市场。 相似文献
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面向21世纪的现代卫星移动通信(下)陈如明(邮电部外事司北京100804)3.3MEO-Odyssey系统Odyssey(奥德赛)系统是由美国TRWInc。公司开发的MEO系统,于1991年5月28日向美国FCC提出了使用许可证申请。它由12颗星组成... 相似文献
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LTR集群移动通信系统及其测量陈白1移动台和转发器移动台的许多功能已用逻辑控制器件来完成,不必再用手动控制,所以比传统的对讲机操作方便,如:信道选择,静噪控制等等都是如此。移动台有双工和单工之分,按需要配置。一般每个移动台最多可编入20条信道。美国L... 相似文献
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蜂窝移动通信是电信领域一个最早引入竞争的活跃的市场。本文介绍了6个工业化国家的蜂窝移动通信市场竞争模式,探讨了这一领域的竞争规则。 相似文献
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一、引言 移动通信的发展甚为迅速。在八十年代出现了模拟移动通信系统,这便是所谓的第一代移动通信。这种系统主要用来传输语言信号——即电话,所应用的复用方法是频分复用(FDMA)。到了九十年代便出现了数字通信系统,此即所谓的第二代移动通信,所应用的复用方法是时分复用(TDMA),而在美国采 相似文献
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简要介绍了码分多址(CDMA)数字蜂窝移动通信技术的优点和我国蜂窝移动通信的现状;针对我国蜂窝移动通信扩容的难点,提出可采用900MHz CDMA数字蜂窝移动通信兼容系统进行扩容。 相似文献
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卫星移动通信信道模型研究及仿真分析 总被引:7,自引:6,他引:1
讨论了三种卫星移动通信信道概率模型的特性,对其应用环境及条件进行了分析;并对不同地理环境的信道模型进行了计算机仿真。仿真得到的结论对估算系统的性能指标和链路分析都有一定的意义,对预测各种调制方式以及纠错码方案对系统误码率的影响具有一定的实用价值。 相似文献
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本文对数字蜂窝区移动通信中所采用的纠错技术作简单介绍 ,着重分析了GSM系统中纠错编码技术工作的原理和技术特点。 相似文献
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Multiuser detection techniques are known to be effective to counter the presence of multiuser interference in code division
multiple access channels. Multiuser detectors can provide excellent performance only when the channel impulse responses of
all the users are precisely known. Hence, channel estimation becomes a challenging issue in mobile communication systems.
In this paper, we address the problem of efficient maximum likelihood mobile radio channel estimation at high channel efficiency
that requires a short training sequence along with the known spreading sequence. The proposed system can be employed in both
the uplink and downlink of a heavily loaded multiuser CDMA system. The extension of the approach with unknown users' delays
are also proposed. We present results that show the success of this method in recovering the transmitted bits with a relatively
small number of preamble bits.
Ahmet Rizaner was born in Larnaca, Cyprus, on January 31, 1974. He received the B.S. and M.S. degrees in Electrical and Electronics Engineering
from the Eastern Mediterranean University, Famagusta, North Cyprus, in 1996 and 1998, respectively. He completed his PhD.
degree in Electrical and Electronic Engineering in Eastern Mediterranean University and joined Eastern Mediterranean University
as a lecturer in 2004. He is lecturing in the School of Computing and Technology. His main research interests include CDMA
communications, adaptive channel estimation, and multiuser detection techniques.
Hasan Amca was born in 1961 in Nicosia-Cyprus. He graduated from the Higher Technological Institute in Magosa-Cyprus (which is renamed
later as Eastern Mediterranean University). He joined EMU in 1985 after receiving a M.Sc. (Digital Signal Processing) degree
from the University of Essex in England (1985). He took his Ph.D. (Mobile Communications) from the University of Bradford
where he was on a Commonwealth scholarship. He has been teaching in the Electrical and Electronic Engineering Department of
Eastern Mediterranean University since 1993 where he also served as the vice chairman from Spring 1998 to Spring 2000. He
has been appointed as the Director of the School of Computing and Technology of the EMU since Spring 2000. His research interests
include Multi User Detection of CDMA signals, Adaptive Equalisation, Multi Carrier Systems, Mobile Radio Systems and Networks,
Internet and Information Technology Applications in Education.
Kadri Hacıoğlu was born in Nicosia, Cyprus. He received the B.Sc., M.Sc., and Ph.D. degrees in electrical and electronic engineering from
the Middle East Technical University, Ankara, Turkey, in 1980, 1984, and 1990, respectively. After his two-year military service,
in 1992, he joined the faculty of Eastern Mediterranean University, Magosa, North Cyprus, as an Assistant Professor, and became
an Associate Professor in 1997. While there, he taught several classes on electronics, digital communications, speech processing
and neural networks. During this time, he conducted research on applying fuzzy logic, neural networks, and genetic algorithms
to signal processing and communications problems. From 1998 to 2000, he was a Visiting Professor in the Department of Computer
Science, University of Colorado, Boulder. Here, he taught classes on neural networks and continued his research. Since 2000,
he has been a Research Associate at the Center for Spoken Language Research, University of Colorado. He has authored or coauthored
numerous papers and supervised a dozen M.Sc./Ph.D. theses. His current research interests are concept-based language modeling,
speech understanding, natural language generation, and search methods in speech recognition/understanding. He also does research
on multiuser detection and equalization in CDMA systems.
Ali Hakan Ulusoy was born in Eskişehir, Turkey, on June 3, 1974. He graduated from the double major program of the department of Electrical
and Electronic Engineering and department of Physics in Eastern Mediterranean University as the first rank student of Faculty
of Engineering in 1996. He received his M.S. degree in Electrical and Electronic Engineering in Eastern Mediterranean University
in 1998. He completed his PhD. degree in Electrical and Electronic Engineering in Eastern Mediterranean University and joined
Eastern Mediterranean University as a lecturer in 2004. He is lecturing in the School of Computing and Technology. His current
research interests include receiver design, multi-user detection techniques, blind and trained channel estimation in Code
Division Multiple Access (CDMA). 相似文献
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随着信息技术的迅猛发展,无线通信成为越来越重要的通信方式之一,从而对信道提出了更严格的要求。回顾并综述了常用的典型无线信道模型,对各种信道的特点和适应场景进行了详细的分析、对比与总结,为实际应用中根据不同环境选择合适的信道模型提供了参考。最后,对其中一些信道模型的优化方向给出了建议,并对信道模型的应用前景进行了概括与展望。 相似文献
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多输入多输出(Multiple Input and Multiple Output,MIMO)信道的空间相关性极大程度上影响着MIMO系统的性能.基于相关统计建模的空间相关性MIMO信道模型,通过合理的软硬件划分,设计了一种高资源利用率的MIMO信道实时模拟方案,实现了实时MIMO信道模拟器.针对3GPP标准MIMO信道模型进行模拟,硬件模拟结果统计分析表明本方案模拟的MIMO信道特征能够与理论特征很好地吻合,具有良好的模拟精度.可扩展的信道模拟方案能够直接扩展到支持更多天线数目的MIMO信道的实时模拟. 相似文献
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研究了数字信号处理(DSP)在移动通信中的应用,主要是Viterbi信道译码算法(VA)的DSP实现,在研究Viterbi译码算法原理的理论基础上,重点研究了DSP实现方法. 相似文献
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为了提高移动通信系统的性能,通常需要在发射端进行分集。而移动通信中的发射分集一般需要在发射端使用多根天线,但许多无线设备因受尺寸或硬件复杂度的限制,一般只有单根天线。为此,专家提出了一种新的解决方法——协作通信。该方法使用带有一根天线的移动台,在多用户环境中可以共享其他移动用户的天线,这样可产生多根虚拟发射天线,进而得到相应的分集增益,改善移动通信系统的性能。 相似文献
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卫星移动通信信道模型和误码率特性分析 总被引:9,自引:0,他引:9
在对卫星移动信道传输特性统计模型研究分类的基础上,给出了适合卫星移动信道的部分阴影扩展模型。用试验和修正的方法给出了模型参数,得到的模型适用于非静止轨道变仰角信道,分析了非静止轨道卫星通信系统窄带调制和宽带扩频调制的误码率性能,得到了有意义的结论。 相似文献