共查询到19条相似文献,搜索用时 140 毫秒
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空间信道模型SCM(Spatial Channel Model)是3GPP用于LTE系统仿真的MIMO二维信道模型。本文在SCM模型的基础上,综合考虑基站端和移动台端电波的离开角和到达角的三维特性,给出了三维MIMO信道模型的信道参数描述,提升了信道建模的准确度,并推导出该信道模型下包含极化特性的MIMO信道系数表达式。同时探究了天线间距、水平角扩展、俯仰角扩展等对MIMO信道空时相关性的影响。研究结果显示,随着俯仰角扩展从0°到60°增大,散射环境越来越强,信号在空间的色散度越高,不同天线单元接收到的信号之间的相关性越小,信道容量将会越大。 相似文献
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现有的多输入多输出(MIMO)信道仿真模型主要基于二维(2D)平面,不能反映实际的三维(3D)电波传播环境。在WINNER 2D模型的基础上研究建立3D MIMO信道仿真平台。加入空间垂直维后,天线方向图需要从2D扩展至3D,并对3D天线阵列构成的MIMO系统进行建模。利用实验数据对城市微小区场景进行仿真验证,可以看出三维MIMO信道参数仿真与实验结果符合较好。3D MIMO信道间的相关性要比2D大,但3D MIMO的信道容量相比2D会有比较大的提升。 相似文献
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室内可见光MIMO信道的空间相关性分析 总被引:4,自引:0,他引:4
该文针对室内可见光多输入多输出(MIMO)信道的空间相关性展开研究,基于朗伯辐射模型,建立了室内可见光MIMO信道模型;并基于该模型,分析了发送与接收空间相关性与空间距离参数的关系,给出了发送与接收相关系数的表达式,为室内可见光MIMO通信系统的布设提供了理论指导;信道矩阵条件数仿真验证了信道空间相关性随发光二极管(LED)间距的减小而增大、随光电检测器(PD)间距的减小而增大、随LED到PD垂直距离的增大而增大;信道容量仿真得出,随着LED与PD数量的增加,信道容量逐步提高,但随着信道空间相关性的增强,信道容量的提高逐步减小。 相似文献
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ATSC组织通过实测,综合考虑了内径相关性、多普勒频移、莱斯因子以及交叉极化因子等因素对系统性能的影响,得到了移动场景和固定场景的广播网MIMO无线信道模型。而基于这两种场景的信道模型还没有统一的评估方法用于后续研究和优化。文中对这两种场景的信道模型进行了仿真,提出了这两种场景的相应评估方法。对于移动场景的Helsinki2信道模型,由于其移动的特性,选取一段时变信道作为一个仿真周期,评估其链路吞吐量性能。对于固定场景的MGM信道模型,测试50条静态信道,按95%的覆盖率来确定其信噪比区间,以此评估系统性能。文中对信道模型的系统仿真以及提出的评估方法,将对后续的研究和优化工作有重要作用。 相似文献
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针对多输入多输出无线信道的空时相关性,文章提出了一种改进的MIMO无线信道模型。该模型利用改进的Jakes模型仿真器来产生独立同分布零均值的复高斯随机变量,从而保证各个传播路径间的相关性很小。仿真结果表明改进的MIMO无线信道模型能够准确的描述出空时相关的MIMO无线信道的统计特性,即空间相关性随天线单元间距增大而战小,随散射信号角度扩展增大不是一致减小. 相似文献
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本文针对采用多标签天线的多输入单输出RFID通信进行了研究。首先,基于超高频RFID传输的EPCglobal标准,建立了RFID通信的传输链路模型,并讨论了2种规格的后向散射数据编码/解码原理;然后,提出了RFID通信的信道模型,并讨论了基于所提出信道模型实现的2种信道结构及其与RFID通信相关的衰落信道模型,重点讨论了MISO系统中的前/后向链路的相关性及信道的空间相关性;最后,提出了实现多标签天线的RFID通信的分集技术和传播模型。仿真结果表明,分集增益不仅与信道模型和采用的编码方案有关,而且与前/后向链路的相关性及信道的空间相关性密切相关,即随着更鲁棒编码方案的采用和传输信道之间的空间相关性的增大而减小,随着前/后向链路的相关性的增大而增大。 相似文献
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提出一种三维移动-移动场景的非平稳多输入多输出(multi-input multi-output, MIMO)信道模型,该模型改进了不同信道状态之间衰落相位的连续性,可保证输出多普勒频移的正确性。同时,针对该新模型研究了非平稳衰落特性引起的时变空时相关性,并针对收发端信号角度谱服从通用Von Mises Fisher(VMF)分布情况,详细推导了归一化空域互相关函数和时域自相关函数的表达式。最后,针对低速和高速移动两种场景的仿真结果表明,获得的理论结果与数值仿真具有很好的拟合度, 但能极大地减低计算复杂性,进而有效提高了分析和仿真复杂动态场景下MIMO 通信系统的效率。 相似文献
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Cooperative MIMO channel models: A survey 总被引:3,自引:0,他引:3
Cheng-Xiang Wang Xuemin Hong Xiaohu Ge Xiang Cheng Gong Zhang Thompson J. 《Communications Magazine, IEEE》2010,48(2):80-87
Cooperative multiple-input multiple-output technology allows a wireless network to coordinate among distributed antennas and achieve considerable performance gains similar to those provided by conventional MIMO systems. It promises significant improvements in spectral efficiency and network coverage and is a major candidate technology in various standard proposals for the fourth-generation wireless communication systems. For the design and accurate performance assessment of cooperative MIMO systems, realistic cooperative MIMO channel models are indispensable. This article provides an overview of the state of the art in cooperative MIMO channel modeling. We show that although the existing standardized point-to-point MIMO channel models can be applied to a certain extent to model cooperative MIMO channels, many new challenges remain in cooperative MIMO channel modeling, such as how to model mobile-to-mobile channels, and how to characterize the heterogeneity and correlation of multiple links at the system level appropriately. 相似文献
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多输入多输出(MIMO)技术应用于移动通信系统中可以提高频谱利用率,增加通信系统的容量.提高用户传输速率,因此,该技术已经成为后3G的关键技术之一。其信道容量不仅和通信环境有关。而且和阵元间信道响应的相关系数有很大的关系。为了对设计的MIMO系统进行评估,则需对其性能进行测试。提出了根据测试相关系数,间接得出信道传输矩阵H的方法。并在实验室环境下,以多天线系统为例。通过采集试验数据。对相关系数做了分析计算。 相似文献
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MIMO信道在巷道中的GBDB模型分析 总被引:1,自引:0,他引:1
多输入多输出(MIMO)技术可以有效减弱无线传输多径衰落现象。建立矿井巷道环境下MIMO信道的三维GBDB模型,推导了该模型的空时相关函数,并对矿井下MIMO信道容量进行了数值仿真。结果表明,矿井巷道中的空间相关性对MIMO系统容量的影响很大,增加接收端天线数量、增大天线间距可以大幅度提高系统的信道容量。 相似文献
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Weichselberger W. Herdin M. Ozcelik H. Bonek E. 《Wireless Communications, IEEE Transactions on》2006,5(1):90-100
Abstract-This paper presents a novel stochastic channel model for multiple-input multiple-output (MIMO) wireless radio channels. In contrast to state-of-the-art stochastic MIMO channel models, the spatial correlation properties of the channel are not divided into separate contributions from transmitter and receiver. Instead, the joint correlation properties are modeled by describing the average coupling between the eigenmodes of the two link ends. The necessary and sufficient condition for the proposed model to hold is that the eigenbasis at the receiver is independent of the transmit weights, and vice versa. The authors discuss the mathematical elements of the model, which can be easily extracted from measurements, from a radio propagation point of view and explain the underlying assumption of the model in physical terms. The validation of the proposed model by means of measured data obtained from two completely different measurement campaigns reveals its ability to better predict capacity and spatial channel structure than other popular stochastic channel models. 相似文献
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The channel capacity of a multiple-input-multiple-output (MIMO) communication system depends substantially on correlation between individual receive branches. We investigate the MIMO capacity using the correlation matrix approach and the Salz-Winters (1994) spatial correlation model. It is shown that for a linear array, correlation has no impact on the MIMO channel capacity provided that the two-element array beamwidth is smaller than the angle spread of the incoming signals. Simple but accurate approximations for the correlation coefficient and the corresponding channel capacity are derived for different angular spreads 相似文献
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A direction of arrival based (DoA-based) beamforming of massive MIMO was proposed for high-speed railway scenarios.In order to guarantee that the optimal system capacity can be obtained during traveling,an iterative multi-beams scheme was proposed.It aimed to design different beams for different mobile carriage terminals (MCT) respectively.The proposal adaptively selected the number of antennas for each beam,and adaptively designed the number of beams according to system capacity.Moreover,the scheme didn’t need channel state information (CSI) that can reduce system implementation complexity and cost.Numerical results indicate that the proposed scheme is suitable for high-speed scenarios,the system performance can be improved more efficiently compared to conventional methods. 相似文献