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潘毅斌 《电信工程技术与标准化》2009,22(9):65-69
智能天线技术是第三代移动通信标准TD-SCDMA的标志性技术,是TD—SCDMA标准相对于其他标准的最大区别和优势,具有增加系统容量、扩大系统覆盖范围、络逐渐商用,智能天线技术也愈加成熟。本文阐述了TD势,并通过DSP和FPGA分别实现了自适应算法。改善服务质量等一系列优点。随着TD-SCDMA网SCDMA移动终端智能天线的一些知识及相关的优 相似文献
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智能天线是在自适应滤波和阵列信号处理技术的基础上发展起来的,是通信系统中能通过调整接收或发射特性来增强天线性能的一种天线。我国提交的第三代移动通信标准TD-SCDMA系统的关键技术之一就是智能天线技术,文章详细介绍了智能天线的历史及其发展,深入分析了智能天线在TD-SCDMA中的运用,最后对智能天线的应用前景进行了展望。 相似文献
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智能天线技术对TD-SCDMA系统容量的改善 总被引:3,自引:0,他引:3
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. 相似文献
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基于智能天线技术的TD-SCDMA系统是目前无线通信领域研究的热点。为了研究TD-SCDMA系统,通过分析TD-SCDMA系统概况、关键技术和智能天线技术的方法,得出智能天线技术己被确认为TD-SCDMA系统的关键技术之一。该技术将会在未来移动通信系统中发挥重要的作用。 相似文献
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TD-SCDMA智能天线系统原理、实现及现场测试方案浅析(上) 总被引:1,自引:0,他引:1
简要介绍了智能天线原理在TD-SCDMA系统中的实现情况,并结合智能天线物理特性,TD-SCDMA智能天线相关仿真数据和几个典型现场测试用例,对TD-SCDMA系统智能天线技术的原理、实现及功能验证进行了分析. 相似文献
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协作通信解决了普通单天线移动终端的空间分集问题,使单天线移动终端在多用户环境中可共享其他终端的天线,从而得到多天线分集增益,改善了移动通信系统的性能.本文从协作通信的概念和原理出发,提出了一种基于协作通信的虚拟多天线(VAA)TD-SCDMA系统,探讨了该系统中各层的实现和面临的挑战. 相似文献
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3G终端的功耗是业界非常关心的问题.本文首先分析了无线通信系统对终端发射功率的要求,然后从调制解调方式、智能天线、双工方式及功率控制等几方面对GSM、TD-SCDMA、WCDMA系统终端功耗做了比较全面的对比分析研究,分析结果表明TD-SCDMA终端的功耗性能不仅远优于2G的GSM,而且优于WCDMA. 相似文献
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研究了两种基于不同准则下的JT和智能天线下行波束成形联合优化方案,首先给出了采用智能天线的TD-SCDMA下行链路模型,在此基础上给出了两种不同准则下的联合优化算法,然后推导出了权向量,最后就TD-SCDMA系统应用环境进行了仿真和分析,并对两种方案进行了比较分析。这两种方案不仅可以减少智能天线主波束内存在的多用户干扰,而且可以降低移动台的复杂度。 相似文献
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Xiong Lizhi Qi Lanfen Zhu Huabin 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(12):2095-2104
The following paper introduces a smart antenna system with MUSIC algorithm for indoor millimeter wave communication. The smart antenna system separates main transmission paths towards receiver by antenna array. Maximal-ratio combination (MRC) of the separated transmission paths provides nearly optimal performance of receiver. Multipath distortion and noise can be greatly reduced by the system. 相似文献
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In this paper, a novel merger of multicarrier code-division multiple access (MC-CDMA) and smart antenna arrays is introduced. Here, a group of Q carriers in the MC-CDMA system is applied to its own M-element smart antenna array at the base station (BS). The smart antennas are located in close proximity to one another. We generate a transmit diversity gain at the receiver by carefully moving (oscillating) the antenna array's pattern. The pattern oscillation is achieved by applying appropriate time-varying phases to array elements of each smart antenna. The beam pattern oscillation ensures a mainlobe at the position of the intended user and small oscillations in the beam pattern. This beam pattern oscillation leads to a time-varying channel with a controllable coherence time; hence, a transmit diversity benefit, in the form of a time diversity benefit, is available at the receiver. Employing MC-CDMA with the proposed smart antenna at the BS, we achieve: 1) directionality which creates high network capacity via space-division multiple access; 2) a transmit diversity gain which supports high performance at the receiver in the mobile unit; and 3) increased capacity and performance via MC-CDMA's ability to support both CDMA and frequency diversity benefits, respectively. 相似文献
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Razavilar J. Rashid-Farrokhi F. Liu K.J.R. 《Selected Areas in Communications, IEEE Journal on》1999,17(4):662-676
There has been considerable interest in using antenna arrays in wireless communication networks to increase the capacity and decrease the cochannel interference. Adaptive beamforming with smart antennas at the receiver increases the carrier-to-interference ratio (CIR) in a wireless link. This paper considers a wireless network with beamforming capabilities at the receiver which allows two or more transmitters to share the same channel to communicate with the base station. The concrete computational complexity and algorithm structure of a base station are considered in terms of a software radio system model, initially with an omnidirectional antenna. The software radio computational model is then expanded to characterize a network with smart antennas. The application of the software radio smart antenna is demonstrated through two examples. First, traffic improvement in a network with a smart antenna is considered, and the implementation of a hand-off algorithm in the software radio is presented. The blocking probabilities of the calls and total carried traffic in the system under different traffic policies are derived. The analytical and numerical results show that adaptive beamforming at the receiver reduces the probability of blocking and forced termination of the calls and increases the total carried traffic in the system. Then, a joint beamforming and power control algorithm is implemented in a software radio smart antenna in a CDMA network. This shows that, by using smart antennas, each user can transmit with much lower power, and therefore the system capacity increases significantly 相似文献
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介绍了基于MIMO的智能天线收发机结构及最新进展,探讨了下一代移动通信系统智能天线技术的发展趋势以及所面临的问题。 相似文献
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一个基于软件无线电的智能天线接收系统 总被引:1,自引:1,他引:1
智能天线技术是第三代移动通信中的核心技术之一,最初主要应用于雷达和军用抗干扰通信。随着软件无线电技术的发展,采用全数字处理,在基带通过对接收和发送信号的波束赋形,可以极大提高无线通信系统的容量和抗干扰能力。文中在讨论智能天线的基本原理和设计思路的基础上,提出并实现了一个适于扩频通信的智能天线接收系统。系统硬件平台的搭建以及固定波束形成的实现,为以后的软件算法的性能评估打下了基础。 相似文献
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ZHENG Sheng-hua XU Da-zhuan JIN Xue-ming 《中国电子科技》2007,5(1):33-37
The developments of the high speed analog to digital converters (ADC) and advanced digital signal processors (DSP) make the smart antenna with digital beamforming (DBF) a reality. In conventional M-elements array antenna system, each element has its own receiving channel and ADCs. In this paper, a novel smart antenna receiver with digital beamforming is proposed. The essential idea is to realize the digital beamforming receiver based on bandpass sampling of multiple distinct intermediate frequency (IF) signals. The proposed system reduces receiver hardware from M IF channels and 2M ADCs to one IF channel and one ADC using a heterodyne radio frequency (RF) circuitry and a multiple bandpass sampling digital receiver. In this scheme, the sampling rate of the ADC is much higher than the summation of the M times of the signal bandwidth. The local oscillator produces different local frequency for each RF channel The receiver architecture is presented in detail, and the simulation of bandpass sampling of multiple signals and digital down conversion to baseband is given. The principle analysis and simulation results indicate the effectiveness of the new proposed receiver. 相似文献
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Zekavat S.A. Nassar C.R. Shattil S. 《Vehicular Technology, IEEE Transactions on》2002,51(5):1030-1039
We introduce a novel merger of smart antenna arrays and multicarrier code-division multiple-access (MC-CDMA) systems. Here, each group of Q carriers in the MC-CDMA system is applied to its own M-element smart antenna at the base station (BS). The smart antennas are separated by a distance that ensures that signals generated by each smart antenna are independent. Applying proper time-varying phases to array elements of each smart antenna array, the beam pattern is carefully controlled to generate a mainlobe at the position of the intended user and small oscillations in the beam pattern. This beam-pattern oscillation creates a time-varying channel with a controllable coherence time and a time diversity benefit at the receiver. Employing MC-CDMA with the proposed antenna array at the BS, we achieve: 1) directionality, which supports space-division multiple access (SDMA); 2) a time diversity gain; 3) increased capacity and performance via MC-CDMA's ability to support both CDMA and frequency diversity benefits. Hence, merging MC-CDMA and BS antenna arrays in an innovative fashion, we achieve high performance at the mobile via joint frequency-time diversity, and high network capacity via joint space-code division multiple access. 相似文献