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Simulation and analysis of node throughput using smart antenna in wireless mesh networks 总被引:1,自引:0,他引:1
ZHANG Yong WEI Yi-fei SONG Jun-de School of Electronic Engineering Beijing University of Posts Telecommunications Beijing ChinaZHANG Li-kun The Translation Department of the Second Artillery Troops of PLA Beijing China 《中国邮电高校学报(英文版)》2007,14(2):28-32
Smart antenna technology is introduced to wireless mesh networks. Smart antennas based wider-range access medium access control (MAC) protocol (SWAMP) is used as MAC protocol for IEEE 802.11 mesh networks in this study. The calculation method of node throughput in chain and arbitrary topology is proposed under nodes fairness guarantee. Network scale and interference among nodes are key factors that influence node throughput. Node distribution pattern near the gateway also affects the node throughput. Experiment based on network simulator-2 (NS-2) simulation platform compares node throughput between smart antenna scenario and omni-antenna scenario. As smart antenna technology reduces the bottle collision domain, node throughput increases observably. 相似文献
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Wei Kuang Lai Kuo‐Shu Tseng Jiunn‐Ching Chen 《Wireless Communications and Mobile Computing》2009,9(2):197-208
The deployment of directional antennas offers many advantages, such as transmission range extension, co‐channel interference reducing, the increasing of spatial reuse degree, throughput improving of networks, and transmission power saving. Hence, many ad hoc MAC protocols with directional antennas have been proposed. However, these protocols do not provide significant improvement of network performance due to the lack of supporting multiple transmissions and receptions simultaneously. With the adaptive beam‐forming system (Smart Antenna), a newly designed MAC protocol (MARS) that enables nodes with multiple transmissions and receptions is proposed. Simulation results show that our MARS do exploit the advantage of space division multiple access. In terms of total number of data forward and complete sessions in bottleneck nodes, MARS achieves three times better than Novel and nine times better than IEEE 802.11. In addition, the end‐to‐end delay keeps very short. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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本文分析了常见的MEMS天线及其应用,包括多对称锥形弯曲缝隙微带天线、用于WLAN中的微尺度宽频天线、开关式微机械毫米波天线、微机械自适应贴片天线等,对这些天线的结构原理、制造方法及其性能做了分析。这些天线设计简单、可用CMOS工艺制造、利于集成,兼有宽频、高辐射效率、小尺度等优点。但相对普通天线而言,这些制造工艺明显复杂、尺度更微小,增加了实现难度,要实现MEMS天线批量应用,还需要在基础理论及其微细工艺进行研究。最后,对MEMS天线在无线通信系统中的应用作出展望。 相似文献
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Chien‐Ching Chiu Yi‐Xiang Tong Yu‐Ting Cheng 《International Journal of Communication Systems》2019,32(9)
In this paper, ultrawide band (UWB) communication systems with eight transmitting and receiving ring antenna arrays are implemented to test the bit error rate and capacity performance. By using the ray‐tracing technique to compute any given indoor wireless environment, the impulse response of the system can be calculated. The synthesized beamforming problem can be reformulated into a multiobjective optimization problem. Self‐adaptive dynamic differential evolution (SADDE) and particle swarm optimization (PSO) are used to find the excitation current and the feed line length of each antenna to form the appropriate beam pattern. This pattern can then reduce the bit error rate and increase the channel capacity and receiving energy. Numerical results show that the fitness value and the convergence speed by the SADDE are better than those by the PSO. Moreover, the SADDE had better results for both line‐of‐sight and nonline‐of‐sight cases. In other words, compared with PSO, SADDE has improved more effectively the main beam radiation energy and reduced the multipath interference. 相似文献
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提出了用分布于 x?y?z 三轴上的三个阵元估计扩频信号各条多径的来波方向(DOA)的方法,以及用由 x?y 均匀平面圆阵和 z 轴直线阵组成的阵列天线形成 3 维波束的方法。根据 CDMA 信号模型和多径信道模型,用 最大似然(ML)法分别估计出信号到达 3 个阵元的复信道响应,并利用复信道响应的幅角来估计各条多径信号 的 DOA;然后在已有最小均方误差(MMSE)法和最小二乘(LS)法的基础上生成带限制条件的扩展 MMSE(EMMSE)法形成 3 维波束。模拟表明,给出的 DOA 估计方法具有很高的精度,而 EMMSE 方法形成的波束主 瓣窄,旁瓣被抑制,有很高的输出信干噪比。 相似文献
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本文首先概述了多径信道传输特性,在此基础上,重点讨论了基于智能天线抗多径干扰技术的理论,并对基于CMA算法的智能天线抑制多径干扰进行了计算机仿真。 相似文献
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本文通过对TD-SCDMA系统上行链路进行系统级仿真,输出了不同场景下相邻小区和本小区干扰比均值,以此对比分析了智能天线和定向天线对小区间和小区内干扰的抑制情况,并给出有关工程措施建议,为TD-SCDMA系统组网提供指导性意见。 相似文献
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《中国邮电高校学报(英文版)》2014,21(6):1-8
Massive multiple-input multiple-output (MIMO) requires a large number (tens or hundreds) of base station antennas serving for much smaller number of terminals, with large gains in energy efficiency and spectral efficiency compared with traditional MIMO technology. Large scale antennas mean large scale radio frequency (RF) chains. Considering the plenty of power consumption and high cost of RF chains, antenna selection is necessary for Massive MIMO wireless communication systems in both transmitting end and receiving end. An energy efficient antenna selection algorithm based on convex optimization was proposed for Massive MIMO wireless communication systems. On the condition that the channel capacity of the cell is larger than a certain threshold, the number of transmit antenna, the subset of transmit antenna and servable mobile terminals (MTs) were jointly optimized to maximize energy efficiency. The joint optimization problem was proved in detail. The proposed algorithm is verified by analysis and numerical simulations. Good performance gain of energy efficiency is obtained comparing with no antenna selection. 相似文献
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智能天线发射数字多波束形成方法研究 总被引:6,自引:6,他引:0
智能天线技术应用于第三代移动通信系统中具有可以减小因频率复用造成的共信道干扰(CCI)、提高频谱利用效率及增大系统容量、减小发射功率和空间电磁干扰、增加发射效率、对小区进行动态划分等优点。阵列天线的数字多波束形成技术是智能天线中的一项重要技术,关于接收数字多波束形成处理技术国内外相关文献报导较多,而对于发射数字多波束形成技术报导较少。文中主要讨论了两种发射数字多波束的形成方法,并通过计算机仿真试验验证该方法的可行性。此方法对蜂窝定位,空分多址系统的实现也有实用价值。 相似文献
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基于弹载智能天线系统对阵列接收信号的分析处理,运用空间谱估计理论,首先估计出信号源数与信号源角度信息。同时与载机加载目标信号源信息进行对比,分离出干扰源。最后将上述估计信息应用于波束控制理论中,实现天线阵列的主波束控制和方向图零点控制,使天线阵列真正实现智能接收的能力。 相似文献
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支持向量机(SVM)是一种新的机器学习方法。介绍了支持向量机的基本原理,通过使用SVM对接收信号的数据处理,得到波束形成器的最佳权向量解,达到存在干扰的情况下波束形成的理想效果。利用SVM求解AR模型中的系数,对波达方向的估计具有良好的稳健性。 相似文献