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这是一部权威的英文版移动通信教程，内容讲解翔实全面，适合对英语和移动通信感兴趣的爱好者

目前最新的物联网信息技术教程，全面权威，适合对此有爱好的朋友，希望大家喜欢

An overview of the application of smart antennas in DS-CDMA systems, including IS-95 and IS-2000, is presented. Since CDMA systems are interference-limited, adaptive antenna arrays have great potential for improving the performance of such systems in terms of capacity, coverage, and quality of service. In this paper, we study the multiple-access interference that affects a CDMA system, and we describe how smart antennas can be implemented in an IS-2000-based mobile communica- tions system. When smart antennas are used at the base station to transmit in narrow beams, the interference on the downlink is reduced, and Cjl is improved. This, in turn, increases the system capacity on the downlink or, alternatively, the quality of service is improved. Such gains will prove very beneficial for asymmetric high-speed data applications. requiring much higher bit rates on the downlink than on the uplink. By reducing the base-station receiver's sensitivity, smart antennas can boost the capacity of the reverse link. Results are presented that outline how this reduction can be employed by the system designer on the uplink to increase capacity, reduce the mobile transmit power, or effect a tradeoff between capacity improvement and coverage or range extension under different system-loading scenarios.

Abstract—In this paper, we present a performance analysis of a smart antenna system operating in a wide-band CDMA wireless- local-loop channel using a beam-forming module (BFM) that has been implemented on a digital signal processor (TMS320C6701) board.We first show the results of computer simulations obtained from the modeled received (RX) signals through a test-bed system consisting solely of baseband signal processing parts, i.e., modeled RX data-generating PC, BFM for computing the optimal weight vector and interfacing module. A test-bed system of the entire base station is then implemented to evaluate the adaptive beam-forming function with the actual wireless signals. This test-bed system in- cludes several subscribers, as well as the array antenna, RF mod- ules, and other receiving parts required at the cell site.

Adaptive-antenna techniques offer the possibility of increasing the performance of mobile radio communication systems by maximising directional gain and enhancing the protection towards multipath conditions. The net effect of these techniques is to improve immunity to interference, extend the range of each cell and thus increase the system capacity. This paper presents the results of a two year research programme aimed at the development of practical adaptive-antenna signal-processing structures. Specifically, results obtained from a series of analysis and field trial activities undertaken with an adaptive antenna test bed and based around the DECT cordless standard are presented.

Abstract—In wireless communications, smart antenna systems that employ antenna arrays coupled with adaptive signal-pro- cessing techniques at the basestation improve capacity, coverage, and trunking efficiency.However, design and performance analysis of smart antenna systems strongly depend on channel propaga- tion characteristics of signals present at the antenna array, the so-called vector channels. Here, variation of narrow-band vector channels (spatial signatures) due to a moving terminal is studied in

Abstract—In mobile communication systems, downlink (for- ward link) system capacity is limited by the ability of mobile receivers to recover the desired signal in the presence of cochannel interference (CCI). Joint detection of the desired and cochannel signals is a useful approach to improving receiver performance, thus increasing system capacity. In this paper, we show that a practical single-antenna joint-detection receiver can provide significant gains in system capacity for the time-division mul-

A parameter learning method is introduced and used to broaden the region of operability of the adaptive control system of a flexible space antenna. The learning system guides the selection of control parameters in a process leading to optimal system performance. The method is applica- ble to any system where performance depends on a number of adjustable para- meters. A mathematical model is not necessary, as the learning system can be used whenever the performance can be measured via simulation or experiment.

Abstract—In this paper, we analyze spatial multiplexing tech- ques for the downlink of a multiple-input–multiple-output MIMO) orthogonal frequency-divisionmultiplexing (OFDM) sys- m. Our study is focused on outdoor environments characterized y a moderate angular spread. We consider two techniques that e able to separate the downlink data streams associated with fferent users and to guarantee a fixed error probability by ploiting limited feedback from each user. The grid of beams GoBs) and the proposed adaptive GoB (AGoB) differ in the ay the precoders are designed (by adaptive or fixed processing) nd in their scheduling policy. The new AGoB is able to harness artial knowledge of the downlink channel spatial structure to etter select the users and adjust their precoders for downlink ansmission. The performances of GoB and AGoB are compared

A wideband adaptive isolator for a UHF RFID reader with a minimum component count is introduced. The operation of the device is based on a reflection from a variable load, which is connected to a port of a hybrid coupler. The other ports are connected to the receiver (RX), transmitter (TX) and antenna ports of the reader. The isolator provides an isolation of 50 dB from TX to RX at the 800 MHz–1 GHz band,covering the worldwide UHF RFID bands. The adaptive system ensures high isolation up to an antenna return loss of 6 dB, or reflection coefficient of 0.5. The measured loss in the TX-to-antenna and antenna-to-RX paths is 4 dB.

Adaptive antennas are often implemented with the Applebaum-Howells-type adaptive processor usually include a hard limiter between each antenna port and its correlation mixer, primarily for dynamic range compression. Brennan and Reed 131 analyzed the effects of hard limiting, and their conclusions suggest that it does not degrade the steady-state performance of the adaptive processor.Standard and hard-limited processors are compared and it is shown that when the two types of processor have the same sensitivity threshold, the hard-limited one can fail to provide sufficient interference cancellation when the correlation matrix of input signals has two or more eigenvalues of differing magnitudes. The consequence of hard limiting is that (depending on the processor design parameters) the larger of two or more signals can capture the hard limiter, allowing the smaller signals to pass through the processor essentially unattenuated. It is also shown that when a hard-limited processor is designed to provide the same cancellation as a standard one, it must have essentially as large a dynamic range as the standard processor; therefore, it offers no advantage of dynamic range compression. Moreover, the hard-limited processor lacks a constant

本世纪五十年代中期创立了仿生学，许多科学家从生物中寻求新的用于人造系统的灵 感一些科学家分别独立地从生物进化的机理中发展出适合于现实世界复杂问题优化的模 拟进化算法(Simulated Evolutionary Optimization)，主要有Holland}l'2} ; Bremermann}3〕等创立的遗传算法，Rechenberg仁‘〕和Schwefel}'〕等创立的进化策略以及Fogel}s} , Owens ,Walsh}'〕等创立的进化规划，同时代有一些生物学家Fraser}s} , Baricelli}'〕等做了生物系统进化的计算机仿真，很遗憾他们没有引入到人工系统.遗传算法、进化策略及进化规划均来源于达尔文的进化论，但三者侧重的进化层次不同，其中遗传算法的研究最为深入、持久，应用面也最广。

最新最全 源程序很实用的丁玉美数字信号处理教程的电子教案，拥有不后悔

基于凝视红外成像制导工作的原理,论述了凝视红外成像末制导系统虚拟样机及其工作环境建模方法,介绍了红外成像制导仿真系统数学软硬件环境和仿真方法,给出了初步的数学仿真结果,对开展凝视红外成像末制导系统技术研究具有指导意义。

国内目前最为权威的红外导弹成像技术，属于绝密资料，请勿外传

常用IC查询式电子设计必须的，但是由于型号多，查询常常不方便，把这个查询形成PPT，查询非常快捷简单。从74系列到54系列

利用无线电技术对飞机、船舶或其他运动载体进行导航和定位的系统。无线电导航技术的基本要素是测角和测距，因此可以组成测角-测角、测距-测距、 测角-测距、测距差（双曲线）等多种形式的系统。无线电信号Esin(ωt+嫓)中振幅E、角频率ω、相位嫓和时间t,都可作为导航参量使用。赋予无线电波以导航信息的方法很多，但都是利用无线电波传播的直线性及其恒定的传播速度两种特性。无线电导航的基准点可以设在地面、空间或卫星上。

智能天线（SmartAntenna或IntelligentAntenna）最初应用于雷达、声纳及军用通信领域。近年来，现代数字信号处理技术发展迅速，DSP芯片处理能力的不断提高和芯片价格的不断下降，使得利用数字技术在基带形成天线波束成为可行，促使智能天线技术开始在无线通信中广泛应用。

详细的内容讲解，图文并茂案例分析，深入浅出，受益匪浅

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