共查询到20条相似文献，搜索用时 15 毫秒
1.
本文由MIMO无线通信信道容量的表达式,给出一种估算式。通过数值仿真对估算值与精确值进行比较,进行误差分析,得出估算值是较精确的,可用估算表达式可靠地预测MIMO信道的容量。 相似文献
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A novel compact planar dual‐band multiple input multiple output (MIMO) antenna with four radiating elements for 5G mobile communication is proposed. Each radiating element has a planar folded monopole, which is surrounded by L‐shaped meta‐rim extended ground stubs. The compact folded arms act as the main radiating elements, while combined with the L‐shaped meta‐rim stubs, the proposed antenna forms multiple resonances so as to achieve dual‐band coverage. The simulated and measured results show that the proposed antenna has two wide bands of ?6 dB return loss, consisting of 1.6 to 3.6 and 4.1 to 6.1 GHz, respectively. Without any additional isolation structure between the elements, the isolation for the proposed 2 × 2 MIMO antenna in both desired bands can be achieved better than 12 dB. The measured results show that the proposed MIMO antenna with good performance, that is, stable radiation patterns, high efficiencies, low specific absorption ratio (SAR) to human tissues, is suitable for WLAN/LTE, 4G and future 5G mobile phone applications. 相似文献
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根据多天线(MIMO)信道空间相关特性,提出一种虚拟子信道的分析方法,从子信道角度探讨信道容量在发射端已知信道响应时预期的性能改善;在此基础上,提出一种逼近信道容量上限的波束形成方法,发掘MIMO信道矩阵最大奇异值与波束形成矢量潜在的联系,并从理论角度详细分析了单用户与多用户最大奇异值联合分布特性,实现阵列增益、空间分集和多用户分集充分融合;仿真与分析表明,利用用户间潜在的随机分布特性能有效提高用户的空间分集增益,提高系统资源利用率,对系统性能改善显著. 相似文献
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A 10‐element multiple‐input multiple‐output (MIMO) handset antenna array with triple‐band operation in the long‐term evolution band 42 (3400‐3600 MHz), band 43 (3600‐3800 MHz), and band 46 (5150‐5925 MHz) is studied in this article. Acceptable antenna performances are obtained by using polarization and pattern diversity techniques. To assess the multiplexing performances of the handset array in 5G, an 8‐element base station array covering 3.4‐7.1 GHz is presented and studied. An 8 × 10 MIMO system incorporating 8 transmit antennas, propagation scenario and 10 receive antennas is successfully reported, and its multiplexing performances are evaluated. The computed channel capacities in the low and high bands can be as high as 43.3 bps/Hz and 41.6 bps/Hz, which are promising for multi‐gigabit‐per‐second (multi‐Gbps) data transmission in 5G. The effects of user's hand and low MIMO order on the channel capacities are also investigated. Results show the robust performances of the proposed antenna system. 相似文献
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邱哲涛 《计算机光盘软件与应用》2012,(3):57+51
本课题概要介绍了新时代移动通信系统的概念以及特点,并在文中详细研究了新时代移动通信系统的关键技术,旨在通过本课题的研究对新时代移动通信系统的关键技术进行总结。 相似文献
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作为未来5G通信的核心技术之一,大规模多输入多输出(multiple-input multiple-output,MIMO)技术获得了广泛的研究。但是,"大规模"带来显著性能增益的同时,也给接收机设计带来了挑战,尤其是考虑到资源和成本限制,基站天线在满足性能需求的同时,需要尽可能少。论文首先讨论了MIMO情景下的传统检测算法,如最大似然(maximum likelihood, ML)检测算法、迫零(zero-forcing, ZF)检测算法及线性最小均方误差(linear minimum mean square error, LMMSE)检测算法等。仿真结果表明最优的ML算法的复杂度随着用户数指数增加。在接收天线数不是充分多时,次优的ZF和LMMSE算法都会有显著的性能损失。针对这一问题,讨论了基于深度学习框架的解决方案,包括目前已有的LAMP(learned approximate message passing)检测算法和神经网络DetNet算法;基于全连接网络结构做了初步探索。经过对它们的仿真比较,发现基于深度神经网络的MIMO检测算法,确实可以提升传统检测算法的性能;但对神经网络系数的优化,可能会导致较高的训练复杂度,论文讨论了可能的解决方法。 相似文献
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Massive antenna arrays can be used to meet the requirements of 5G, by exploiting different spatial signatures of users. This same property can also be harnessed to determine the locations of those users. In order to perform massive MIMO localization, refined channel estimation routines and localization methods have been developed. This paper provides a brief overview of this emerging field. 相似文献
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An eight‐element antenna array based on open/closed slot modes that can cover the 3.5 GHz band (3400‐3600 MHz) is proposed and studied. There are two kinds of antenna elements with the slot sizes of 10.8 × 1 mm2 and 28.8 × 1 mm2 for open and closed slot modes, respectively. Both the two kinds of antenna elements are realized with the help of the metal frames with the height of 7 mm at the two long sides of the ground. The proposed antenna array is suitable for 5G metal frame mobile phone applications. A prototype is fabricated and measured. The measured results show that all the eight antenna elements can cover the band of 3400‐3600 MHz and the isolations are bigger than 13 dB, the measured efficiencies all are bigger than 42% and the measured envelope correlation coefficients are lower than 0.15. 相似文献
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为了解决3G移动通信系统具有一定的局限性,提出了4G移动通信系统。介绍了4G的特点,对比了3G与4G各种技术指标。重点阐述了4G的网络结构和关键技术,包括OFDM等。 相似文献
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第五代移动通信系统（The fiith generation mobilecommunication system, 5G）测试作为整个通信产业链的关键一环,能够对5G全网设备以及不断演进的新技术进行验证。它具有灵活多样的测试技术,并能真实全面反映网络状况的特点,为增强5G网络覆盖能力,全面提升网络整体性能提供了强有力的保障。本文先对全球5G发展现状进行简要概述,随后从5G关键技术验证、核心网验证以及接入网验证3个方面对中国的测试发展状况作介绍,详细介绍了新空口的空口辐射（Over the air,OTA）测试技术及其在大规模天线技术（Massive MIMO）上的应用优势。最后,对未来5G测试面临的挑战和发展趋势进行了展望。 相似文献
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正交频分复用（OFDM）是一种特殊的多载波数字调制技术。不像常规的单载波技术,如AM/FM（调幅/调频）在某一时刻只用单一频率发送单一信号,OFDM在经过特别计算的正交频率上同时发送多路高速信号。OFDM技术的最大优点是对抗频率选择性衰落或窄带干扰,同时又提高了频谱利用率。OFDM已经吸引了许多世界级电信设备制造商包括Alcatel-Lucent,Nortel（北电网络）,Cisco,Nokia等公司的极大兴趣和认可,纷纷开始对其关键技术和标准进行研究和开发,希望能够在无线通信领域新的潜在市场中首先占领制高点,一些公司希望OFDM能推动更高速的第四代移动通信系统（4G）的形成。人们开始集中越来越多的精力开发OFDM技术在移动通信领域的应用,在无线宽带接入及未来4G领域中,OFDM技术都将成为继CDMA技术之后的又一核心技术。介绍了OFDM的原理和技术优势,分析了现存几种类型OFDM技术的特点,展望了OFDM标准化和在第四代移动通信系统的应用。 相似文献
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This paper presents a compact 5G multiple‐input multiple‐output (MIMO) microstrip antenna with isolation enhancement based on a slotted complementary split‐ring resonator (SCSRR) and the theory of characteristic modes (TCMs). The metamaterial unit consists of three CSRR connected by extra slots. These added slots improve significantly the rejection response in terms of bandwidth and suppression. The dispersion diagram analysis is introduced to show the filtering characteristics of the band‐gap structure before and after adding these additional slots. The TCM is employed to investigate the behavior of this 5G MIMO antenna before and after adding the slotted CSRR. The TCM is also applied to the MIMO antenna system to build up a precise methodology that can foresee whether the isolation can be upgraded further or not. The slotted CSRR is inserted meticulously in specific locations to block the coupling modes and almost does not affect the results of the noncoupling modes to improve the isolation remarkably. With this slotted CSRR, a 27‐dB reduction in the mutual coupling between the two patch antennas is achieved. The whole design has been simulated utilizing the Microwave Studio CST ver. 18 simulator. The antenna being proposed is highly efficient and suitable for 5G wireless communication. 相似文献
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阿娜古丽·阿布拉 《网络安全技术与应用》2014,(2):7-7,9
在第4代移动通信技术（4G）飞速发展的今天,MIMO（MultipleInputMultipleOutput,多输入多输出）技术由于其在通信领域的先天技术优势,被广泛的应用于无线通信技术中。文章从MIMO从无线通信技术的发展引出MIMO的概念,详细介绍了MIMO的系统原理、关键技术应用研究、发展前景等。 相似文献
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在还没有完全享受3G移动通信系统商所带来服务的同时,4G移动通信技术的研究已经在逐步的进行着。该文简要分析了:(1)4G的网络结构;(2)4G的关键技术,如OFDM,软件无线电,智能天线技术,MIMO技术。(3)比较了3G和4G不同指标,分析了3G和4G采用的不同技术。(4)初步探讨了4G的现状和发展。 相似文献
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A broadband 8‐antenna multiple‐input and multiple‐output (MIMO) system working for 5G new radio N77 (3.3‐4.2 GHz) in mobile terminals is proposed. In particular, each antenna element/unit consists of a monopole‐type meandered branch and an inverted U‐shaped self‐isolated antenna branch; and the antenna unit is fed by the meandered branch. The antenna unit has two resonances generated separately by each branch of the antenna unit. Since the monopole couples strongly with the self‐isolated antenna element that has the inherent self‐isolation characteristics, quite good isolation for the broadband 8‐antenna MIMO system can be obtained. The results such as antenna efficiency, radiation patterns, envelope correlation coefficient, and channel capacity are also presented. 相似文献
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A small‐size four‐element antenna system for 2 × 2 LTE low band (LB, 698‐960 MHz) and 4 × 4 LTE middle/high band (M/HB, 1710‐2690 MHz) multiple‐input multiple‐output (MIMO) operations in 5G (fifth‐generation) mobile terminals is presented. The proposed antenna system is formed by two identical tunable loop antennas and two identical coupled‐fed IFA (Inverted‐F Antenna) antennas. By loading a RF switch with four output states as tunable component, the proposed loop antenna can not only operate in the M/HB, but also achieve improved bandwidth coverage in the LB. Each coupled‐fed IFA element operating in the M/HB with compact volume. The four antennas are placed on the both short side‐edge of the mobile terminal with small ground clearance of 4.2 mm. The simulated S‐parameters show that the proposed MIMO system can cover 698 to 960 MHz and 1710 to 2690 MHz with reflection coefficients less than ?6 dB and isolations are all more than 12 dB. Good MIMO performances such as radiation efficiencies, envelope correlation coefficient (less than 0.4 within the entire operation bands) and channel capacity are also obtained. The effects of user's hand(s) on performances for the proposed antenna system are also discussed. This four‐element antenna system prototype is fabricated and measured. 相似文献
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随着移动通信技术的发展,第五代移动通信(5G)网络正式商用并规模建设.作为5G的一项关键技术,Massive MIMO技术具有系统容量大、覆盖范围广、抗干扰能力强的优点.在介绍Massive MIMO技术及波束赋形的基础上,对Mas-sive MIMO设备形态进行分析,结合设备造价、用户价值、终端分布、品牌口碑等,提出... 相似文献
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The fifth-generation (5G) wireless technology is the most recent standardization in communication services of interest across the globe. The concept of Multiple-Input-Multiple-Output antenna (MIMO) systems has recently been incorporated to operate at higher frequencies without limitations. This paper addresses, design of a high-gain MIMO antenna that offers a bandwidth of 400 MHz and 2.58 GHz by resonating at 28 and 38 GHz, respectively for 5G millimeter (mm)-wave applications. The proposed design is developed on a RT Duroid 5880 substrate with a single elemental dimension of 9.53 × 7.85 × 0.8 mm3. The patch antenna is fully grounded and is fed with a 50-ohm stepped impedance microstrip line. It also has an I-shaped slot and two electromagnetically coupled parasitic slotted components. This design is initially constructed as a single-element structure and proceeded to a six-element MIMO antenna configuration with overall dimensions of 50 × 35 × 0.8 mm3. The simulated prototype is fabricated and measured for analyzing its performance characteristics, along with MIMO antenna diversity performance factors making the proposed antenna suitable for 5G mm-wave and 5G-operated handheld devices. 相似文献