智能天线小型化的发展

本文首先简要介绍了TD-SCDMA智能天线的原理及面临的问题,然后对目前几种主要的智能天线小型化方案进行了分析,并给出了作者的建议.     

TD-LTE智能天线小型化应用研究

本文研究的小型化智能天线,基于微带陶瓷智能天线设计思路,通过引入多重微型结构,明显提高了单阵元辐射效率,从而使得在天线增益接近常规智能天线条件下,天线整体体积缩小到常规智能天线的1/4左右.LTE试验网测试和应用研究表明,目前该小型化智能天线各指标已达到或接近常规大天线水平,已基本具备规模组网试商用能力,在城区、密集城区及建站困难区域有着广阔而良好的应用前景.     

关于智能天线小型化的探讨

近年来智能天线成研究热点,文章首先从空间自由度出发,指出在给定孔径下增加天线并不能提高空间资源,然后分析了在互耦增强的情况下,互耦补偿效果将显著下降,最后指出空间自由度和天线间的互耦是限制智能天线小型化的工程因素。     

智能天线小型化研究

智能天线技术致力于解决迅速增加的业务量和有限的频谱资源之间的矛盾,在实际应用中,智能天线的体积问题一直是业界关注的焦点.     

UHF天线的小型化分析

针对超高频机载合成孔径雷达天线小型化、高增益和宽频带的问题,分析了短背射天线缩小背腔的增益损失.根据pottel 推算的公式,计算了馈源反射盘遮挡的增益损失.提出了用一种由宽偶极子构成的H型天线二元阵来取代短背射天线中的引向结构.指出了这种结构不仅能够提高天线增益、展宽频带还能缩小天线结构.比较了国内外小型超高频合成孔径雷达天线的结构.研究表明,利用宽偶极子和微带组阵能为有限平台提供重量轻、结构小、增益高和宽频带的超高频合成孔径雷达天线.     

不同应用场景下智能天线的选择

1 前言 智能天线良好的抗多用户干扰性能使其成为TD-SCDMA系统的关键技术之一,并对网络性能有着重要影响.采用智能天线技术可以加大小区覆盖半径,减少基站数目,降低建设成本.     

智能天线技术在移动通信中的应用

智能天线采用空分复用技术,利用信号在传播方向上的差异,将同频率、同时隙的信号从空域区分开来。它可以成倍的扩展通信容量,并和其它复用技术相结合,最大限度的利用有限的频谱资源;可以有效地克服移动通信中由于复杂的地形、建筑物结构等对电波传播的影响,以及时延扩展、多径衰落、共信道干扰等产生的不利影响;能有效地扩大信号覆盖范围,降低系统建设成本;还能进行紧急呼叫定位,并提供更高的定位精度,可开发更多的增值业务。因此其在各种移动通信系统中得到了广泛的应用。     

浅析智能天线

主要介绍了智能天线的提出背景、基本概念、关键技术、优点以及国外的研究进展情况，最后指出了智能天线的发展方向。     

智能天线小型化策略之双极化天线

首先介绍智能天线小型化的必要性,然后利用电磁仿真软件的仿真结果分析城区环境下极化信道的特性以及极化天线带来的极化分集效果,最后讨论双极化智能天线的结构和应用双极化智能天线应关注的问题.     

智能天线技术

介绍了智能天线技术的发展,智能天线的基本分类及算法,以及智能天线的实现方式。     

智能天线在OFDM系统中的应用

将智能天线引入OFDM系统可以克服限制系统容量的符号间干扰(ISI)和同道干扰(CCI)。文中首先介绍了数字波束形成,其次介绍了OFDM系统,最后介绍了智能天线自适应系统在OFDM系统中的位置和权值的计算问题。     

智能天线技术对TD-SCDMA系统容量的改善

近年来,智能天线技术已成为移动通信中最具吸引力的技术之一,使用智能天线可以大大降低移动系统内的干扰,提高系统的性能和容量.基于TD-SCDMA系统,对系统的干扰及载干噪比进行了分析,重点对不同路径损耗以及误码率下,基站采用智能天线技术对系统容量的改善进行了计算和仿真.仿真结果表明,在相同的路径损耗和误码率下,采用智能天线技术可以显著地提高TD-SCDMA系统的容量.     

智能天线及其在卫星通信抗干扰中的应用

由于智能天线能在空域内有效地抑制干扰的同时提高接收信号的信干比，从而成为下一代卫星通信系统空间段不可缺少的一种抗干扰手段。本着重阐述了星载智能天线的基本概念，关键技术及研究近况，最后还指出了有待研究的课题和今后的发展方向。     

移动通信中的智能天线技术

智能天线技术已经成为移动通信领域中最具吸引力的技术之一，它能够根据所处的电磁环境，智能地调节自身参数，抑制干扰，提高天线增益，增加频谱利用率，从而改善移动通信系统的性能。介绍了智能天线的工作原理，阐述了智能天线常用的算法、数字波束成型技术、对系统性能的改善以及在移动通信系统中的应用，最后对智能天线的未来作了展望。     

智能天线自适应波束赋形算法的研究

智能天线作为3G及未来移动通信的核心技术，是当前通信领域的研究热点。阐述了智能天线的基本原理，并对自适应波束赋形算法进行了分类，较为详细地比较和分析了几种算法的特点及其适用条件。基于算法的现状，提出了未来的研究方向。     

Interference Mitigation on WLANs Using Smart Antennas

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.     

智能天线对CDMA通信系统性能的改善

作为一种发展较快的技术,智能天线技术在移动通信领域中引起了广泛关注,它能够根据所处的电磁环境,智能的调节自身参数,抑制干扰,提高天线增益,增加频谱利用率,从而改善移动通信系统的性能。介绍了智能天线的工作原理、性能和特点,讨论了在CDMA系统中采用智能天线后系统信噪比性能和容量的改善情况。     

智能天线辅助的PN 码同步捕获新方法研究

为有效解决强干扰环境下长PN 码的同步捕获问题,研究了基于自适应滤波器的PN 码同步捕获方法,给出了基于自适应滤波器权矢量范数的同步捕获判决准则,与传统的基于均方误差的判决相比,这种方法可以大幅提高判决的正确概率。在此基础上,研究了智能天线权值与PN 码同步联合捕获算法,并对其性能进行了计算机仿真验证,结果表明这种空时联合的捕获算法可以有效实现低SINR 环境下的长PN 码捕获。     

智能天线内置一体化合路校准网络

为解决传统合路器体积重量与损耗不能兼顾的问题,提出了一种用于智能天线的内置一体化合路校准网络,采用微带结构,由带阻合路器和校准网络组成。实测结果表明,合路校准网络的通带插损小于0.7dB、通带回波损耗小于-15dB、阻带抑制大于30dB。该一体化合路校准网络具有集成度高、体积小、重量轻、工艺简单等特点,有利于减小智能天线的体积及重量。     

Smart Antennas with Two-Dimensional Array Configurations for Performance Enhancement of a Joint Detection CDMA Mobile Radio System

Smart antennas for base stations of cellular mobile radio systems offer the potential of system performance enhancement by taking advantage of the directionally inhomogeneous signal reception at the receiver. In this paper, two-dimensional array configurations employed at the uplink receiver of a joint detection CDMA (JD-CDMA) mobile radio system are investigated. This smart antenna concept can be split up into a novel channel estimator and data detector which incorporate explicitely the information of the direction-of-arrival (DOA) of signals emerging from users assigned to the considered base station. Proceeding from channel models that model the directional inhomogeneity of the mobile radio channel with single DOAs, the link level performance of a JD-CDMA mobile radio system using this smart antenna concept is evaluated for the rural propagation environment. The performance evaluation is based on Monte Carlo simulations of data transmission and average bit error rates versus the average signal to noise ratio per net information bit are presented for different array configurations. Although these results should be considered as upper bounds for the link level performance, they reveal the advantages of implementing two-dimensional array configurations at the uplink receiver of a JD-CDMA mobile radio system.