Description: ，OFDM系统的各子信道信号的分离（解调）是靠这种正交性来完成的。另外，OFDM的个子信道上还可以采用多进制调制（如频谱效率很高的QAM），进一步提高了OFDM系统的频谱效率。第二，实现比较简单-, OFDM system channel signal separation (demodulation) is relying on this orthogonality to be completed. In addition, OFDM the sub-channel can also use M-ary modulation (such as high spectrum efficiency and QAM), to further improve the spectrum efficiency of OFDM system. Second, to achieve relatively simple Platform: |
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Author:崔卫 |
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Description: 认知无线电是一种通过与其运行环境交互而改变其发射参数提高频谱利用率的新的智能技术。-Cognitive radio is viewed as a novel approach that can change its transmitter parameters based
on interaction with the environment where it operates and can alSO improve its spectrum access and efficiency． Platform: |
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Author:deng |
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Description: Cognitive Radios (CRs), which sense the spectrum and
implement opportunistic sharing when no licensed user is
found to use it, are able to improve the efficiency of
spectrum. Spectrum sensing must be firstly solved in CRs.
Cooperative sensing can make good use of network
resources, obtain higher gain and make the network steadier Platform: |
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Author:phong |
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Description: 对讲机在诸多行业领域广泛应用。虽然模拟对讲机现今仍垄断市场，但数字通信以其更丰富的业务种类，更好的业务质量、保密性和连接性，尤其可提高频谱效率，更有效利用宝贵的频谱资源，因此对讲机数字化是大势所趋。这里介绍一种基于CC1101射频器件的数字无线对讲机的语音通信技术。-Radio widely used in many industries. Although the current analog radio is still monopolizing the market, but a richer digital communications with its business lines, better service quality, security and connectivity, in particular, can improve the spectrum efficiency, more efficient use of valuable spectrum resources, it is the trend of digital radio . Here CC1101 RF devices based on digital wireless walkie-talkie voice communication technology. Platform: |
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Author:dffgdds |
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Description: 认知无线电是一种用于提高无线电通信频谱利用率的新的智能技术. 首先简述认知无线电的背景和概念,针
对认知无线电的频谱感知功能,详细地分析基于能量检测的频谱检测方法,在此基础上研究了噪声方差的不确定
性对检测性能的影响. 针对无线信号检测具有本地局域性和能量检测存在信噪比极限的特点,提出一种分布式有
限合作检测机制,推导出基于“OR”规则的有限合作机制的检测概率,并进行Monte Carlo仿真.-Cognitive radio is a radio communications spectrum used to improve the efficiency of the new smart technology. First, the background and outlined the concept of cognitive radio, spectrum sensing for cognitive radio capabilities, a detailed analysis of the spectrum based on energy detection test In this study the noise variance based on the uncertainty of the detection performance. for wireless signal detection with local detection of localized and there is signal to noise ratio limit of the energy characteristics of a distributed cooperative detection mechanism, derived out based on " OR" rules of the detection probability of the limited cooperation mechanism and conduct Monte Carlo simulation. Platform: |
Size: 749568 |
Author:林熙怡 |
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Description: 认知无线电是一种用于提高无线电通信频谱利用率的新的智能技术. 首先简述认知无线电的背景和概念,针
对认知无线电的频谱感知功能,详细地分析基于能量检测的频谱检测方法,在此基础上研究了噪声方差的不确定
性对检测性能的影响. 针对无线信号检测具有本地局域性和能量检测存在信噪比极限的特点,提出一种分布式有
限合作检测机制,推导出基于“OR”规则的有限合作机制的检测概率,并进行Monte Carlo仿真.-Cognitive radio is a radio communications spectrum used to improve the efficiency of the new smart technology. First, the background and outlined the concept of cognitive radio, spectrum sensing for cognitive radio capabilities, a detailed analysis of the spectrum based on energy detection test In this study the noise variance based on the uncertainty of the detection performance. for wireless signal detection with local detection of localized and there is signal to noise ratio limit of the energy characteristics of a distributed cooperative detection mechanism, derived out based on " OR" rules of the detection probability of the limited cooperation mechanism and conduct Monte Carlo simulation. Platform: |
Size: 183296 |
Author:林熙怡 |
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Description: 一种关于GMSK调制技术研究，为了进一步提高频谱的利用效率，设计了一种改进的GMSK-A kind of GMSK modulation technique, in order to further improve the spectrum efficiency, design an improved GMSK Platform: |
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Author:杜永斐 |
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Description: 协作频谱感知虽然可提高系统的感知性能， 但随着感知节点数目的增加， 系统资源的占用越来越多，
系统传输效率下降． 分析了协作频谱感知方法的感知性能， 得到协作频谱感知的感知性能与感知节点数目和接
收信噪比之间的关系， 提出了一种新的次级用户节点的选择方法， 该方法有效保证了所选择节点的感知性能，
仿真验证了该算法的有效性和可靠性．-Although the cooperative spectrum sensing can improve the perceived performance of the system, but with the perception of the number of nodes increases, more and more system resources, the system transmission efficiency decreased. Cooperative spectrum sensing method of analysis of the perceived performance of collaborative spectrum sensing by the perception of performance and perception of the number of nodes and the relationship between the received SNR, a new secondary user node selection method, which effectively guarantee perceived performance of the selected node, the simulation proves the validity and reliability. Platform: |
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Author:江中 |
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Description: 为了提高MIMO-OFDM系统的数据传输率和频谱利用率,提出一种新的自适应算法。该算法在保证信道质量所需误码率和总发射功率的前提下,按照各个子载波衰落程度动态地分配比特和功率,使系统的总数据传输速率最大。理论分析得出,该算法降低了系统运算复杂度,能很大地改善系统的整体性能。-In order to improve data transmission rates and spectrum efficiency of MIMO-OFDM systems,this paper proposes a new adaptive algorithm. While the channel transmission quality to meet the requirements of a certain target BER(bit error rate) and total emissive power,according to each sub-carrier decline degree to adjust each sub-carrier modulation method freely,try to minimize the total data rate of system. Theory analysis shows the algorithm can reduce system complexity and improve overall performance of the ... Platform: |
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Author:王睿 |
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Description: 应用基于LabVIEW的虚拟仪器的构建方法，搭建和开发了音频信号频
谱测试系统，并与传统音频频谱仪所测得的频谱进行比较。系统的研发成功，能
极大地提高了频谱测试的效率，保证了测试系统的准确性、稳定性及安全性，且
具有成本低廉和开发周期较短的特点，对设计和研发类似测试系统具有一定的推
广价值。同时，本文给出了系统软硬件的设计方案，做出了可行的解决方案。-Application based on LabVIEW virtual instrument approach to building structures and the development of audio signal spectrum measurement system, and with the traditional audio spectrum analyzer spectrum measured for comparison. The successful development of the system, can greatly improve the efficiency of spectrum testing to ensure test accuracy, stability and security, and has a low cost and shorter development cycle characteristic of the design and development of similar test system has a certain promotional value. Meanwhile, this paper presents the system hardware and software design to make a viable solution. Platform: |
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Author:zhuyuanyuan |
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Description: 正交频分复用(OFDM)是第四代移动通信的核心技术,它是实现宽带无线通信和多媒 体业务发展的基础。对OFDM 技术的基本原理，关键技术以及实现进行了研究，并且通过 matlab 中的通信仿真系统simulink 对OFDM 系统进行了模拟和分析，直观和形象地得到了 OFDM 系统在时域和频域的传输性能，得出的结果表明OFDM 系统可以明显地表现出抗多 径效应引起的频率选择性衰落和提高了频谱利用率，这一特性使得它能够在高数据传输速率 的无线信道中发挥优势。-Orthogonal Frequency Division Multiplexing (OFDM) is the fourth generation mobile communication core technology, which is broadband wireless communications and multimedia development. The basic principle of OFDM technology, key technology and implementation have been studied, and by matlab simulink simulation system in the OFDM communication system was simulated and analyzed, intuitive, and get the image of the OFDM system in time domain and frequency-domain transmission performance , the results show that OFDM system can be apparent in the anti-multipath effect caused by frequency selective fading and improve the spectrum efficiency, this allows it to transmit at high data rate wireless channel advantage. Platform: |
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Author:foxlili |
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Description: 轻武器权限申请程序等外侧段v二大王我我的2的1我-In cognitive radio networks, power control is considered as an important issue to improve the performance of dynamic spectrum sharing. In this paper, in order to maximize the efficiency of the system, the secondary users and primary user behaviors will be considered. Platform: |
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Author:武款 |
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Description: 网对此说道稳定调查单位为氮测定法v稳定成为当刺猬刺猬刺猬侧完成单位从汶川-In cognitive radio networks, power control is considered as an important issue to improve the performance of dynamic spectrum sharing. In this paper, in order to maximize the efficiency of the system, the secondary users and primary user behaviors will be considered. Platform: |
Size: 3072 |
Author:武款 |
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Description: 额度为单位对身材C阿萨css彻底删除维多西奇舞动长裙策维持稳定从万达cdc档次低vvcd-In cognitive radio networks, power control is considered as an important issue to improve the performance of dynamic spectrum sharing. In this paper, in order to maximize the efficiency of the system, the secondary users and primary user behaviors will be considered. Platform: |
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Author:武款 |
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Description: MIMO．OFDM系统的子载波、功率和比特分配
MIMO技术能不增加系统带宽却提高系统容量和频谱利用率-The MIMO.OFDM system subcarrier, bit and power allocation
MIMO technology can not increase the bandwidth of the system can improve the system capacity and spectrum efficiency Platform: |
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Author:sunyidu |
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Description: Spectral Efficiency Analysis in OFDM and
OFDM/OQAM based Cognitive Radio Networks
The future wireless communication is expected to
be able to improve the efficiency of spectrum usage. To solve the challenge of spectrum shortage, an innovative opportunistic spectrum access strategy, called Cognitive Radio (CR) has been proposed. Platform: |
Size: 165888 |
Author:Honaleum |
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Description: 在风基本特性的理论基础上,应用Shinozuka方法对大跨结构的广义脉动风进行了模拟,引入快速傅立叶变换(FFT)技术以提高计算效率,同时给出了Matlab程序框架,并把模拟谱与目标谱进行比较验证,两者吻合较好.-Based on the theory of the basic characteristics of the wind on the application of the generalized method Shinozuka fluctuating wind span structures were simulated, the introduction of the fast Fourier transform (FFT) techniques to improve computational efficiency and given Matlab program framework and the simulated spectrum comparing the target spectrum validated both in good agreement. Platform: |
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Author:李雷 |
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Description: neural network ,Spectrum prediction in the cognitive radio system
attracts more and more attention. It can predict future spectrum
holes to save energy of spectrum sensing and to improve the
efficiency of spectrum access. Platform: |
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Author:suman |
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Description: 在现代无线通信技术中，扩频通信是一种具有较强抗干扰性能的技术，正交频分复用(OFDM)是一种具有较高数据传输速率和频谱利用率，并能有效对抗频率选择性衰落的多载波调制技术，因而将这二者结合起来构建系统势必会进一步提高系统的抗干扰和抗衰落性能，研究其结合技术也逐渐成为无线通信领域的热点。随着3G的兴起，即将推出的LTE也将采用OFDM技术（正交频分多路复用）。
由于OFDM的多载波特性，使得直接序列扩频技术和跳频技术能够与OFDM技术进行有效的结合。在本文中,我们研究了OFDM）以及相关抗干扰抗衰落技术。同时用matlab进行了仿真，仿真结果表明，本文提出的ICI干扰消除技术在ofdm中起到了很好的效果。
-In modern wireless communication technologies, spread spectrum communication is a kind of strong anti-jamming technology, the performance of orthogonal frequency division multiplexing (OFDM) is a kind of high data rate and spectrum efficiency, and can be effective against frequency selective fading of multi-carrier modulation technology, and combine the two build system is bound to further improve the system s anti-interference and decay resistance, and study the combining technology also gradually become a hot spot in the field of wireless communications. With the development of 3 g, the upcoming LTE will also use OFDM (orthogonal frequency division multiplexing) technology.
Because OFDM multi-carrier characteristic, the direct sequence spread spectrum and frequency hopping technology can be combined with OFDM technology effectively. In this article, we studied the OFDM technology) and related anti-interference resistance to decline. Matlab simulation was carried out at the same tim Platform: |
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Author:wfyan |
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Description: 扩频通信在现代无线通信技术中是一种具有较强抗干扰性能的技术，正交频分复用(OFDM)一种具有较高数据传输速率和频谱利用率，并能有效对抗频率选择性衰落的多载波调制技术，因而将这二者结合起来构建系统势必会进一步提高系统的抗干扰和抗衰落性能，研究其结合技术也逐渐成为无线通信领域的热点。随着3G的兴起，即将推出的LTE也将采用OFDM技术（正交频分多路复用）。
由于OFDM的多载波特性，使得直接序列扩频技术和跳频技术能够与OFDM技术进行有效的结合。在本文中,我们研究了OFDM）以及相关抗干扰抗衰落技术。同时用matlab进行了仿真，仿真结果表明，本文提出的ICI干扰消除技术在ofdm中起到了很好的效果。
-In modern wireless communication technologies, spread spectrum communication is a kind of strong anti-jamming technology, the performance of orthogonal frequency division multiplexing (OFDM) is a kind of high data rate and spectrum efficiency, and can be effective against frequency selective fading of multi-carrier modulation technology, and combine the two build system is bound to further improve the system s anti-interference and decay resistance, and study the combining technology also gradually become a hot spot in the field of wireless communications. With the development of 3 g, the upcoming LTE will also use OFDM (orthogonal frequency division multiplexing) technology. Platform: |
Size: 489472 |
Author:wfyan |
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Search - improve spectrum efficiency