共查询到19条相似文献,搜索用时 78 毫秒
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本文首先概述了多径信道传输特性,在此基础上,重点讨论了基于智能天线抗多径干扰技术的理论,并对基于CMA算法的智能天线抑制多径干扰进行了计算机仿真。 相似文献
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智能天线技术是第三代移动通信中的关键技术之一。本文从移动通信环境传播的特点出发,分析了智能天线如何克服恶劣的移动环境以及它对提高系统覆盖范围,减少干扰,提高系统容量等方面所起的作用。本文还介绍了智能天线技术中的自适应算法。 相似文献
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CDMA系统中自适应阵列天线的改进算法 总被引:2,自引:0,他引:2
为改善调节阵列天线阵元权向量自适应算法的收敛稳定性,提出了一个改进算法。该改进算法不仅稳定、简单,而且能大大降低误码率。仿真结果对改进算法给予了有力的支持。 相似文献
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智能天线在移动通信中的应用 总被引:3,自引:0,他引:3
本文对智能天线的原理和分类进行了简要介绍,着重探讨了应用智能天线技术对移动通信网络特别是GSM网络性能的改善作用,并由此对在GSM系统中使用智能天线技术的意义进行了分析,文章还对智能天线技术在TD-SCDMA系统中的应用及其特点进行了分析。 相似文献
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文章分析了在基站使用智能天线来提高CDMA多小区系统的容量。文中考虑了多径干扰、热噪声、路径损耗、处理增益和语音激活因子的影响。理论分析和数值模拟表明,在基站使用智能天线能够极大地提高CDMA多小区系统的性能。 相似文献
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This paper investigates the performance of a fixed Wireless LAN in which nodes are equipped with fully adaptive smart antennas. The considered smart antenna system is a uniform circular array of microstrip patch elements in which the weights are updated using the unconstrained LMS algorithm. The behavior of a new directional MAC protocol for spatial multiplexing is analyzed and compared with IEEE 802.11 DCF. The paper purpose is the evaluation of interference and multipath effects on SDMA, using realistic models for the channel and for the smart antenna system. The link model takes into account path loss, cochannel interference and multipath, using a modified Jakes model. Results show that the performance of the WLAN are strictly dependent on the interferer characteristics and on the angular spread of the channel.
Fulvio Babich was born in Trieste, Italy. He received the doctoral degree in electrical engineering, from the University of Trieste, in 1984. From 1984 to 1987 he was with the Research and Development Department of Telettra (Vimercate), working on optical communications. From 1987 to 1992 he was with Research and Development Department of Zanussi (Zeltron), where he held the position of Company Head in the Home System European projects. In 1992, he joined the Department of Electrical Engineering (DEEI) of the University of Trieste, where he is associate professor of digital communications. His current research interests are in the field of wireless networks and personal communications.
Massimiliano Comisso was born in Trieste, Italy. He received the degree of “Laurea" in Electronic Engineering from the University of Trieste. Currently, he is a PhD student at the Department of Electrical Engineering (DEEI) at University of Trieste in information technology. His research interests include wireless networks, adaptive arrays and small antennas.
Marco D'Orlando was born in Tolmezzo, Italy, in September 1978. He received the Electronic Engineering degree (summa cum laude) from the University of Trieste, Italy, in December 2003. He is currently working toward the Ph.D. degree in the Department of Electrical and Electronic Engineering (DEEI) at University of Trieste. His research interests are in the field of multimedia communications, networking, joint source channel coding and resource allocation.
Lucio Manià was born in Ronchi dei Legionari, Italy, in 1942. He received the Electronic Engineering degree from the University of Trieste, Italy, in 1968. Since 1970 he has been an Assistant Professor with the Department of Electrical and Electronic Engineering, where he is currently an Associate Professor. From 1975 to 1985 he was a consulting engineer with Co.El. S.p.A., where he was involved in antenna design for FM and TV broadcasting systems. His current scientific interests include electromagnetic compatibility for safety purposes, wireless communications and numerical techniques for electromagnetic simulations. 相似文献
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In a radio communication environment, no matter whether signal is transmitted outdoors or indoors, the phenomenon of multipath interference is unavoidable. Therefore, it is necessary for us to thoroughly study the effect of multipath interference on cellular mobile systems. In this paper, we first investigate the effect of multipath interference on the performance of a single cell system with finite users. In order to use the Markov chain method, a system model with 2-dimensional state vector is presented. With his model, the system performance under multipath interference has been successfully derived. Next, an extended-slot method to reduce the multipath interference triggered by LOS packets occurring in the previous slot is proposed. Numerical results show that this method can remarkably enhance the system performance. Finally, we further analyze the combined effect of co-channel interference and multipath interference on the performance of multicell systems. Numerical results show that the system performance suffers some degradation compared to the single cell environment. However, the degradation under typical environments with path-loss exponent around 4 is insignificant. 相似文献
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对采用智能天线的移动通信系统的电磁干扰性能进行了分析与仿真.仿真结果表明,采用智能天线的移动通信系统可以减少对环境所造成的电磁干扰和电磁污染,并且电磁干扰是随着用户分布而变化的,是有方向性的.与采用传统全向单天线的移动通信系统相比较,采用智能天线的移动通信系统最大干扰抑制比可达14.52dB,平均干扰抑制比为6.94dB. 相似文献
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不采用自适应算法的智能天线系统 总被引:2,自引:0,他引:2
本文提出了一种基于等旁瓣针状波束方向图的智能天线。为了与采用自适应算法的智能天线进行对比,本文分别模拟了这两种不同天线用于CDMA系统时的扩容能力。模拟结果表明,在CDMA系统中无需采用自适应算法,只需用等旁瓣针状波束智能天线,就可以达到与自适应智能天线相似的扩容性能。等旁瓣针状波束智能天线的优点是:无需迭代、响应速度快,鲁棒性好。 相似文献
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针对于提高干扰机收发隔离度的自适应干扰对消系统 ,利用快速FFT技术实现了一种替代时域LMS算法的频域快速LMS自适应算法 ,分析表明该算法不但具有同时域LMS算法近似的收敛特性 ,而且计算量大幅度减少 ,有利于对消系统的实时实现。计算机仿真证实了分析的正确性和该算法的可行性 相似文献
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给出了一种采用信干噪比准则的、集成了预多波束天线与LMS自适应天线的软件天线方案,该方案采用开关合并方法,把软件天线输出接到最大输出信噪比的算法输出,实现算法分集.在TD-SCDMA动态模型上对提出的方法进行了仿真,结果表明,采用集成软件天线方案的误码率性能要优于单纯的预多波束天线或LMS自适应智能天线.仿真过程考虑了用户来波方向和用户到基站距离的动态变化,以及功率控制算法和系统同步过程的影响. 相似文献