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1.
为了减少5G蜂窝网络中不必要的小区切换次数并提高用户平均吞吐量,提出了一种基于熵权的多目标优化小区预切换方案。多目标优化法将下行链路信干噪比、时延、预测驻留时间和小区可用资源作为切换指标,引入向量归一化技术并使用不同的方法处理有益指标与非有益指标,分析并预测最优目标切换小区从而达到预切换目的。与现有的切换方法比较,所提方案降低了排名异常的概率,在提高用户平均吞吐量的同时极大地减少了不必要的切换。  相似文献   

2.
导弹航迹质量的动态评估是选主站数据融合模式下反导预警态势生成的重要环节.根据各雷达对导弹目标在瞬时状态和一定时间段内的探测情况,构建了航迹质量评估指标体系,基于熵权法确定了各指标的客观权重,并将所得权重应用逼近理想解排序法(TOPSIS)进行排序,由此得出航迹质量的优劣.该方法解决了在没有真值信息比对下的实时航迹质量评...  相似文献   

3.
蒋金波  王可人  付欣  熊最 《电讯技术》2012,52(5):761-765
将接近理想方案的序数偏好法(TOPSIS)应用于认知无线电网络的频谱切换中,通过对 影响切换性能的4个参数的融合,设计了一种基于TOPSIS算法的信道排序方案,通过仿真验 证,设计了各参数的权值。统计结果表明,提出的算法在80%的情况下要优于传统的切换算 法,可以有效减少认知用户的切换次数,提高有效数据传输速率,降低认知用户的通信中断 概率。  相似文献   

4.
《现代电子技术》2018,(1):23-27
由于LTE切换过程是支持多个切换准备的,针对在切换过程中无线链路失败后重新成功建立这一问题提出一种具有避免乒乓效应并提前准备切换(EHOPPPA)的算法,该算法重点在于用户可以接收到多个准备切换的目标基站的切换命令信息,并且通过小区选择到最佳的目标基站。通过OPNET仿真该算法可以在切换过程中实现切换失败率降低约60%,并且在没有增加乒乓效应的前提下在切换过程中从无线链路失败中成功恢复的概率接近100%。该算法提高了切换成功率,尤其是在人口密集的地方效果更为显著。  相似文献   

5.
在第五代移动通信(5G)系统中,大规模MIMO天线和超密集部署网络是实现高吞吐量的两种方式。针对超密集网络的切换管理的问题,该文基于网络分簇的思想提出了根据终端设备运动情况动态调节滞后余量的切换管理算法。在该算法中,基于小基站分簇化管理的前提,用户设备在小区间切换分为预切换和正式切换两个阶段,预切换阶段完成最佳目标小区选择、小区资源预留和预鉴权等操作,正式切换阶段根据预切换阶段监测的设备速度动态调节切换门限的滞后余量。仿真结果表明了该算法可以有效降低设备的切换时延和切换失败率。  相似文献   

6.
辐射源威胁评估属于多属性决策问题,逼近理想解排序(TOPSIS)法作为经典的多属性决策方法,在威胁评估中应用广泛,但TOPSIS存在人为设定权重和位于正、负理想点中垂线上的对象无法进行区分排序的问题。针对TOPSIS法的问题,提出了基于变精度粗糙集模型(VPRSM)和相对熵排序法的辐射源威胁评估方法。该方法首先基于VPRSM利用先验辐射源数据信息确定权重;然后,将相对熵引入TOPSIS法对其加以改进,通过相对熵排序法完成威胁评估。实例仿真验证了所提方法的有效性和适用性。  相似文献   

7.
重点对威胁度评估技术特点进行了分析,通过构建空袭目标威胁度评估模型,来研究相关原理和方法拓展,最后通过若干实例分析检验了模型的实用性和合法性,其中威胁度评估模型采用多属性决策方法,对单因素威胁度的量化用隶属函数描述,权值计算采用层次分析法(AHP)与熵权法相结合的方法,并用TOPSIS排序法(优劣解距离法)对目标威胁度进行了排序.  相似文献   

8.
郑恒慧 《中国新通信》2009,11(23):54-60
随着基站密度的越来越高,信号重叠覆盖越来越严重,特别是在高层建筑物之间及室内,由于无线电波折射及反射原因,无线信号杂乱,而且信号波动不稳定,切换序列难以预测。移动台在如此复杂的无线环境当中,很容易引起切换混乱,造成切换掉话。分析掉话的原因可知,引起掉话的很大一部分原因是上行原因掉话及突然掉话。所以有效控制复杂无线环境中的切换,将能大大改善通话的突然掉话。Locating算法专题优化分析,通过原理和试验来说明:如何通过启用及控制上行Locating排队来筛选切换候选小区,筛除下行链路信号较强而上行链路信号较弱的切换候选小区,避免通话切入上下行功率不平衡小区而引起上行信号原因掉话或突然掉话。  相似文献   

9.
TD-LTE基于RSRP/RSRQ的小区切换算法优化   总被引:1,自引:1,他引:0  
张玲 《数字通信》2013,(2):54-58
对TD-LTE(time division long term evolution)的传统切换算法进行改进,改进的新算法综合考虑小区信号强度(RSRP)及小区信号质量(RSRQ),并将目标小区负载作为切换目标小区选择的关键因素。通过仿真进行传统切换算法与改进切换算法的对比,分析得出改进切换算法在切换成功率以及平均切换次数上都有所改进,从而有效地减少了业务中断及乒乓效应。  相似文献   

10.
刘春玲  田玉琪  张琪珍  冯锦龙 《电讯技术》2023,63(11):1803-1810
针对基站之间距离近、网络数量庞大的超密集网络中切换过程存在干扰以及频繁切换问题,提出了一种基于预判决的模糊逻辑切换算法。算法在计算用户接收信号的信干噪比基础上,预筛选出干扰较小的网络,计算用户在筛选出的候选网络中的停留时间,当停留时间大于门限值时对候选网络使用基于模糊逻辑的逼近理想解排序算法。通过模糊逻辑优化网络属性参数,进而使用逼近理想解排序算法对候选网络进行排序。排序过程中,使用修正后的贴近度计算方式使计算结果更加精确。仿真实验证明,该算法在超密集异构网络切换中可以有效降低切换次数,减少网络阻塞概率,有效提升用户服务质量。  相似文献   

11.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

12.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

13.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

16.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

17.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

18.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

19.
The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO>6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.  相似文献   

20.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

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