CDMA系统中自适应阵列天线的改进算法

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。     

TD-SCDMA系统中智能天线的重复迭代自适应算法

提出一种用于TD-SCDMA系统的重复迭代自适应智能天线算法。通过在自适应算法中把阵列输入信号和作为参考信号的训练序列重复使用,可以在短训练序列情况下实现较好的收敛,提高通信系统的传输效率。对LMS算法中全训练序列重复迭代和滑动窗口重复迭代算法进行了仿真,结果表明,在有限训练序列时本算法比传统LMS算法更好地逼近最佳解。     

WCDMA-TDD中的重复迭代自适应智能天线算法

提出一种用于WCDMA-TDD系统的重复迭代自适应智能天线算法.通过在自适应算法中把阵列输入信号和作为参考信号的训练序列重复使用,可以在短训练序列情况下实现较好的收敛,提高通信系统的传输效率.对LMS算法中全训练序列重复迭代和滑动窗口重复迭代算法进行了仿真,结果表明,在有限训练序列时该算法比传统LMS算法更好地逼近最佳解.     

用于CDMA中的智能天线技术研究

讨论了应用于CDMA中的智能天线技术,并且利用高阶统计量和累积分布函数的概念,分析了在多径干扰条件下智能天线的性能.     

WCDMA系统中智能天线PSALS-SDRMTA自适应算法

本文结合3GPP协议针对第三代移动通信WCDMA系统推导出了基于最小二乘准则的导频符号辅助解扰解扩重扩多目标阵列自适应算法,然后对此算法作了仿真,结果证明PSALS-SDRMTA算法是有效的。     

DS—CDMA系统自适应天线波束形成技术及波达方向估计方法研究

基于空间变步长搜索算法提出了一种适用于DS-CDMA系统的自适应波不形成及波达方向估计的改进算法，由于利用了DS-CDMA系统已知用户扩频码这一特点，因此算法的正确率更高，理论分析和仿真结果证明了该算法的正确性。     

CDMA移动通信系统中的智能天线技术研究

给出了智能天线技术的基本概念,对其工作原理和技术特点作了简单介绍,阐述了智能天线常用的算法和相应的准则。研究和分析表明:无线移动通信领域智能天线技术能够分析到达天线阵的信号,优化地使用波束,减少干扰,提高频谱的利用率,改善无线通信系统的性能。最后对智能天线在CDMA移动通信系统中的应用进行了论述。     

移动通信中的智能天线技术

文章首先介绍了智能天线技术中的基本概念及其在移动通信系统中的发展和应用,然后说明了在移动通信系统中,应用智能天线技术可以提高系统的性能和容量,并可以简化系统控制。在此基础上,文章分别介绍了切换智能天线中预置波束的设计方法和自适应天线阵列中的经典自适应算法,并简介了目前智能天线技术的发展现状。     

CDMA系统中的自适应阵列天线技术

介绍了自适应阵列天线——用于CDMA移动通信系统增加容量的新技术，包括这项技术的原理和基本结构等等。     

CDMA蜂窝移动通信技术及其应用

讨论了ＣＤＭＡ技术的发展历程和特点及系统结构，进行了成本分析，指出了ＣＤＭＡ的发展前景。     

关于CDMA蜂窝系统中功率控制的分析

本文就ＣＤＭＡ蜂窝系统中的功率控制问题进行了讨论,其中包括功率控制误差的考虑以及功率控制源的选择,在以往的分析中,常常只考虑基于距离的功率,选择,本文引入了对实际环境下基于导频功率的选择考虑,给出了两种方法的比较,数值计算结果显示后者在系统容量上有一定的改善。     

A Review of the Four Dimension Antenna Arrays

The four dimensional （4D） antenna arrays introduce a fourth dimension, time, into conventional antenna arrays to offer greater flexibility in the design of high performance antenna arrays. This paper presents the tutorial on the study of 4D antenna arrays and the review of the recent research findings on 4D antenna arrays. Issues considered include the theory of 4D antenna arrays, different time modulation schemes, numerical simulation results, and some experimental results on their applications to low sidelobe designs. Throughout the discussion, some challenging issues on the study of 4D antenna arrays arc highlighted.     

A Blind Adaptive QR-Based Lattice Multi-Channel Filter for Cellular Base-Station TDMA Transceivers with Antenna Arrays

A new adaptive algorithm for blind interference rejection and multipath mitigation is studied and applied to antenna array processing in TDMA cellular communication systems. It is shown how the estimation of multiple signals from different sources by means of a multi-sensor receiver can be formulated as a multi-channel deconvolution problem. The proposed method is based on High-Order Statistics (HOS) processing of the baseband vector samples at the antenna array output. The similarity between the cumulant-based solution and the standard multi-variable Least Squares solution is exploited to derive an efficient adaptive algorithm based on the vector lattice architecture. The algorithm is numerically stable, considerably less complex than other existing multi-channel methods using HOS processing and exhibits rapid convergence with respect to blind array processing algorithms using simple gradient-based minimization procedures.     

蜂窝通信的空分多址:概念、算法和性能

蜂窝通信采用空分多址正在移动通信领域引起广泛关注。本文对空分多址的基本概念、空间信道模型及其知识利用、上下行链路的实现方法和算法、以及对系统性能的改善等诸方面,进行了比较全面的论述。对目前空分多址研究中值得关注的问题,表达了作者的观点。     

一种新型三线式宽频带短波基站天线

提出了一种新型三线式宽频带短波基站天线的详细设计过程,对天线进行了仿真分析和实际测试,该天线在2 MHz~30 MHz频带范围内满足电压驻波比小于2.0,相对增益可达3 dBi~5 dBi,比普通宽带短波基站天线工作频带宽、辐射效率高。而且适应于不同用途,三线式短波基站天线具有平拉和倒‘V’两种架设方式。     

Essential Considerations in Implementing the Smart Antenna System for Downlink Beamforming

This paper addresses some essential problems that have to be taken into consideration in implementing the smart antenna base station (SABS) for downlink beamforming. In order to provide proper downlink beamforming as well as uplink beamforming, a pragmatic procedure of automatic calibration is proposed. Through the experimental test, we confirm that the proposed calibration technique has eliminated the problem of the phase differences of the signal path associated with each antenna. Also, in this paper, we first analyze the multipath condition under which the auxiliary pilot becomes indispensable for detecting the data transmitted on the data channel and what happens if the auxiliary pilot is not available. Then, the performance of the downlink beamforming utilizing the auxiliary pilot is analyzed through the computer simulations. Finally, we present a comparison of downlink communications to uplink ones in terms of throughputs available at each of uplink and downlink communications. Weon-Cheol Lee received the B.S, M.S, and Ph.D. degree in Electronic Communication Engineering from Hanyang University, Korea, in 1992, 1994, 2005, respectively. From 1994 to 2000, he was with LG Electronic Inc., where he had worked for developing the digital VCR, digital cable modem, digital TV. Since 2001, he has been a professor with department of information and communications, Yong-in Songdam College, Korea. His research interests include smart antennas, mobile communications beyond the third generation, digital broadcasting technology, and communication signal processing. Dr. Lee also received the Best Research Paper Award and Excellent Research Engineer Award from LG Electronics, respectively. Seungwon Choireceived the BS degree from Hanyang University, Seoul, Korea, and the M.S. degree from Seoul National University, Korea, 1980 and 1982, respectively, both in electronics engineering, the MS degree (computer engineering) in 1985, and the PhD degree (electrical engineering), in 1988, both from Syracuse University, Syracuse, NY. From 1988 to 1989 he was with the Department of Electrical and Computer Engineering of Syracuse University, Syracuse, NY, as an Assistant Professor. In 1989 he joined the Electronics and Telecommunications Research Institute, Daejeon, Korea. From 1990 to 1992 he was with the Communications Research Laboratory, Tokyo, Japan, as a Science and Technology Agency fellow, developing the adaptive antenna array systems and adaptive equalizing filters. He joined Hanyang University, Seoul, Korea, in 1992 as an assistant professor. He is a professor in the School of Electrical and Computer Engineering of Hanyang University. Since 2003, Dr. Choi has been serving as a Vice Chairman and the representative of the ITU region 3 for SDR (Software Defined Radio) Forum and as a Director of the HY-SDR Research Center, MIC, Korea. His research interests include digital communications and adaptive signal processing with a recent focus on the implementation of the smart antenna systems for both mobile communication systems and wireless data systems. Jae-Moung Kim received the BS degree from Hanyang University, Korea in 1974, the MSEE degree from University of Southern California, USA in 1981, and the PhD degree from Yonsei University, Korea in 1987. He was a Vice President of Radio {&} Broadcasting Technology Laboratory and Director of Satellite Communication System Department at Electronics and Telecommunications Research Institute (ETRI) from September 1982 to March 2003. Since April of 2003, he has been a Professor in the Graduate School of Information Technology and Telecommunications, Inha University. He is a board member of directors of Korean Institute of Communication Science (KICS), a Vice President of Korea Society of Broadcast Engineers (KOSBE) and a senior member of IEEE. His research background is telecommunication systems modeling and performance analysis of broadband wireless access systems, mobile communications, satellite communications and broadcasting transmission technologies.     

CDMA移动通信系统中基于RLS算法的天线阵列有源校正

基于递归最小二乘(RLS)自适应滤波理论,本文提出了一种天线阵列的幅度和相位不一致性的有源在线 校正方法。该方法具有快速稳健的收敛性能,不受天线阵列的几何形式限制,也适用于移动用户数大于阵元数的实际通信 环境中。计算机仿真证实了该方法的有效性。     

CDMA蜂窝移动通信系统中的联合功率控制

功率控制技术是CDMA系统克服“远-近效应”,降低多址干扰、增大系统容量的一项关键技术.第三代移动通信系统对功率控制提出了新的研究课题.本文简要介绍了联合功率控制技术的基本概念,重点阐述了目前在多媒体CDMA系统中,联合功率控制与速率控制技术,与多用户检测技术,以及与自适应天线阵列处理技术的研究进展,并分析了目前研究中仍然存在的问题,最后指出了未来的研究方向.     

Directional Diversity of Smart Antenna in LAS CDMA Systems

The performance of code division multiple access (CDMA) systems can be affected by small scale fading such as Rayleigh fading channel. In this paper, the application of smart antenna and Large Area Synchronous CDMA (LAS CDMA) systems, which introduce directional diversity channel, is presented. A novel interference cancellation scheme through dynamic space code (DSC) algorithm is briefly described. The directional diversity can be realized from the directional gain of smart antenna system. It can be found that when the number of elements in smart antenna is increase the directional gain of antenna system is much higher than single antenna. The system performance analysis in term of error probability is compared between traditional and LAS CDMA systems in both single and smart antenna systems. From the performance analysis it is found that CDMA system is more susceptible to multipath fading channel than interferences from existing users.