Capacity of distributed antenna network by using single‐carrier frequency domain adaptive antenna array

Single‐carrier frequency domain adaptive antenna array (SC‐FDAAA) has been proposed and proved in our previous study to be effective in suppressing multiple access interference in a severely frequency selective fading channel. In this paper, we studied the performance of SC‐FDAAA in a distributed antenna network (DAN). To make it clear whether the performance of SC‐FDAAA can benefit from the distributed nature of DAN or not, we made a comparison between DAN and the traditional cellular network, that is, central antenna network. The bit error rate distribution and the system capacity (both link capacity and cellular link capacity) are presented. It is shown that by using the SC‐FDAAA, cellular link capacity is maximized by using single frequency reuse. In addition, the capacity of SC‐FDAAA can also benefit from the distributed nature of DAN. Copyright © 2012 John Wiley & Sons, Ltd.     

Distributed antenna network for gigabit wireless access

For gigabit wireless data services, there are three important technical issues to be addressed: limited bandwidth, severe frequency-selective fading, and limited transmit power. A distributed antenna network (DAN) is a promising solution to the above three technical issues. In DAN, each mobile user is served by using multiple distributed antennas close to it. In this paper, recent advances in various distributed multi-input/multi-output (MIMO) techniques combined with single-carrier (SC) frequency-domain signal processing are presented for DAN. Particular attention is paid to SC frequency-domain MIMO diversity, relay, beamforming, and multiplexing jointly used with frequency-domain equalization (FDE) to significantly improve the signal transmission performance.     

穿墙雷达多维参数人体姿态识别方法

现有的人体姿态识别方案大多数是从单一的角度来考察人体的姿态特征,但是仅采用距离像很难体现人体关节的位置信息,仅提取微多普勒特征有时会覆盖掉径向速度不明显的特征.为此,本文首先利用慢时间-距离像和慢时间-微多普勒谱图构建出人体姿态的三维张量数据集,扩展了人体姿态的特征维度,然后采用改进型瓶颈残差模块构成的神经网络提高了人...     

基于混合核深度适配网络的HRRP目标识别

为了改善基于卷积神经网络（CNN）的雷达目标识别模型的泛化能力,本文将深度适配网络（DAN）方法引入到高分辨一维距离像（HRRP）目标识别中。为了进一步提高DAN方法的性能,创新性地提出了混合核函数MMD代替传统DAN中的多核MMD,设计了基于混合核函数的MMD损失函数。本文使用服从瑞利分布的海杂波来干扰目标域数据。网络模型中使用一维CNN提取特征,使用混合核函数DAN来减少源域和目标域间特征分布的差异。实验表明,相对常规迁移学习方法和DAN方法, 在海杂波影响下该方法可将目标域数据识别率提高15%左右,显著提高了模型的泛化性能和鲁棒性。     

桌域网环境下的ATM互连性能分析

桌域网是９０年代以来兴起的新技术。文章分析了桌域网中从现有ＰＣ总线结构变迁到基于ＡＴＭ技术互国需要的功能特性和,指出ＡＴＭ不能满足某些互连类型的鼗对现有的两种桌域网ＷＡＮ接口方案文章提出一种新型的接口模型。文章还从操作系统方面分析了适应于桌域网环境的软件特性。     

桌域网及其新技术的研究

桌域网是一种适合于多媒体业务需要的小型ATM网 ,是对传统计算机网络的体系结构的一种补充。本文介绍了设计桌域网的基本策略 ,讨论了它的设计目标和特性 ,给出了桌域网的体系结构、网络接入设备及其性能 ,最后提出研究桌域网的几点建议。     

短波小型接收天线设计

常用短波天线的尺寸一般较大,不适用在舰艇、船只和山顶等特殊环境中使用.因此,在不降低性能指标的条件下,需要尽量减小短波天线的尺寸.为此,设计了小型短波宽带有源鞭状天线.结果表明,小型短波宽带有源鞭状天线的性能指标不小于常用的笼形天线,且具有体积小、重量轻、抗毁性强、使用电压低等特点.     

一种X 和Ka 波段频率可重构Koch分形振子天线研究*

将射频开关和Koch分形振子相结合,设计了一款结构紧凑的可工作于X和Ka两个波段的频率可重构天线,所设计的天线长度约为相同谐振频率普通振子天线的80％.天线工作于Ka频段时,由于天线中被射频开关断开的其它部分对其辐射性能的影响严重,会使Ka频段的方向图发生严重变形,因此我们又对天线进行了改进优化.改进后的天线由Koch分形振子和其前端另外延伸增加的一普通振子构成,改进天线在X频段和Ka频段的性能分别由Koch分形振子和普通振子所决定.仿真和实测结果表明:改进优化后的天线在X和Ka两个频段都具有良好的性能.     

The dielectric wedge antenna

A new modification of the TEM-horn antenna has been developed for ground-penetrating radar (GPR) applications. The antenna is based on a dielectric wedge, and thus, was named the dielectric wedge antenna. Tapering of the metal flairs has been used to match the antenna to the ground and to reduce the late-time ringing. The finite-difference time-domain model of the antenna has been created to investigate physical processes within the antenna and to optimize its performance. The dielectric wedge antenna has shown a superior (in comparison with the TEM-horn) performance by radiation in different types of the ground and has been used in a novel antenna configuration within a GPR system, which is dedicated for landmine detection.     

一种宽频带微带天线的设计

介绍了宽频带渐变式微带缝隙天线的工作原理、设计参数及其对电性能的影响，设计了一种结构简单的天线形式，给出了该天线工作于S、C频段的结构尺寸以及VSWR、辐射方向图的仿真和测试数据曲线，两者之间有很好的一致性，并对影响天线性能的关键参数进行了误差计算。结果表明：在加工精度可达到的范围内，对天线性能的影响不大。该天线可应用于宽频带单极化、双极化阵列天线单元或反射面天线馈源。     

GA design of a thin-wire bow-tie antenna for GPR applications

A microgenetic algorithm has been applied to design a new ultrawideband thin-wire bow-tie antenna for ground-penetrating radar applications. The broadband performance of the antenna is achieved by resistive loading and by optimizing the number of wires and the angular distances between those wires. The radiation characteristics of the optimized antenna are discussed, and its performance is compared to that of a resistively loaded Wu-King dipole.     

分形开槽减缩微带天线RCS

分形由于其独特的结构及性能早已在天线的设计中有所应用,但较少地应用于天线雷达散射截面减缩。本文首次将分形思想应用到开槽微带天线中。设计了一副分形开槽微带天线,与常规微带天线相比,在辐射性能降低不多的同时较好地实现了整个频带RCS减缩。     

Highly sensitive, co-optimised active receiver antenna: its use in Doppler radar in 2.4 GHz ISM band

A novel design methodology is presented to co-optimise an active receiver antenna, combining a planar rectangular ring antenna and a low noise amplifier, operating from 2.4 to 2.485 GHz. A Doppler radar experiment based on this active antenna illustrates the excellent noise performance resulting from this approach.     

Array Antenna With Increased Element Separation Based on a Fabry–PÉrot Resonant Cavity With AMC Walls

A new method is presented for increasing the separation between the radiating elements of a 1-D array antenna by incorporating it into a Fabry-Perot type resonant cavity with artificial magnetic conductor (AMC) walls. The AMC walls create a more uniform distribution of field within the cavity and, moreover, eliminate diffracted fields. The concept is demonstrated via 3-D full-wave simulations as well as experimental measurements for a prototype antenna. Comparison between an antenna with AMC walls and an identical reference antenna, without walls, shows a reduction in the sidelobe level. An array element separation of 2lambda is achieved whilst maintaining good radiation performance. The performance of the proposed structure is also compared to that of an antenna incorporating PEC walls. Finally, the effect of the sidewall and central AMC walls are considered separately in order to isolate their corresponding effect on the antenna performance.     

一种分齿蝶形超宽带天线的设计与研究

对一种分齿结构的蝶形平面天线进行了研究设计与验证。通过仿真将该结构天线与普通蝶形天线进行对比,分析了分齿比例参数对其性能产生的影响。结果表明,该类天线可以在保证特定频段驻波比性能的同时,减轻天线的重量。优化设计并制作了工作在300～480 MHz频段的一款天线,测量结果显示,在工作频率范围内,天线馈入端驻波比小于2,相对带宽大于40%,符合超宽带天线设计要求。     

高速多媒体桌域网的结构体系技术研究

桌域网是一种适合于多媒体业务传输的小型高速网络。本文论述高速多媒体桌域网的概念,结构体系和主机接口。在介绍桌域网的设计目标和特性之后着重分析桌域网的结构体系和两种主机接口的特点,并给出其应用前景。     

The effects of reflector antenna diffraction on the interference cancellation performance of coherent sidelobe cancellers

While adaptive antenna technology has undergone significant development, little attention has been given to the impact of antenna design on the performance of the adaptive system. A need exists to factor the details of the antenna system response into the analysis of adaptive system performance, particularly in the case where adaptive cancellation is required over a broad bandwidth. At extremely high frequency (EHF) where wide bandwidth allocations exist, reflector antenna technology used with an adaptive sidelobe canceller design is appropriate. This paper uses a simple diffraction model to compare the adaptive performance differences between Cassegrain and offset reflector designs. The reduced diffraction of the offset reflector design results in improved cancellation performance. These analyses also provide the opportunity to explore the impacts of antenna design parameters and interference power levels and arrival directions.     

TD—LTE系统天馈演进策略探讨

本文首先对TD—LTE（D频段）与TD—SCDMA（F、A频段）共用天馈线的性能进行了理论分析,针对共用天线引起的控制信道（无波束赋形）和业务信道性能变化进行了系统仿真验证,随后针对TD—LTE室内分布的天馈形态进行了分析,最后针对TD—LTE天馈线的工程实施方案进行了探讨。     

非大气窗口毫米波长槽漏波波导天线的设计

设计了一种非大气窗口毫米波长槽漏波波导天线,分析槽的长度、宽度对天线性能的影响,并运用插值法缩减天线槽长,优化天线的性能,减轻天线的重量。优化后的天线具有高增益、低副瓣、窄波束、主波束前倾、E面方向图近似圆形等特点。在结构设计上,采用UG385波导接口连接射频部件,提高馈电与天线的匹配性;同时,对天线内表面进行镀金处理,提高天线表面的光洁度,减小损耗。仿真和测试结果表明,该天线能够满足非大气窗口毫米波雷达对天线的指标要求。     

星载SAR相控阵天线一体化热设计

介绍了星载相控阵天线一体化热设计的方法,利用不同的仿真软件分析了天线热分布、结构变形等情况,通过建立热变形对天线电性能影响的仿真模型,验证热设计是否能满足电性能要求,并以电性能最优为目标实现最优的热设计。最后,针对星载SAR天线产品验证文中设计方法的工程可实现性。