Channel Measurement and Path Loss Modeling from 220 GHz to 330 GHz for 6G Wireless Communications

Terahertz(THz)communication has been envisioned as a key enabling technology for sixthgeneration(6G).In this paper,we present an extensive THz channel measurement campaign for 6G wireless communications from 220 GHz to 330 GHz.Furthermore,the path loss is analyzed and modeled by using two single-frequency path loss models and a multiplefrequencies path loss model.It is found that at most frequency points,the measured path loss is larger than that in the free space.But at around 310 GHz,the propagation attenuation is relatively weaker compared to that in the free space.Also,the frequency dependence of path loss is observed and the frequency exponent of the multiple-frequencies path loss model is 2.1.Moreover,the cellular performance of THz communication systems is investigated by using the obtained path loss model.Simulation results indicate that the current inter-site distance(ISD)for the indoor scenario is too small for THz communications.Furthermore,the tremendous capacity gain can be obtained by using THz bands compared to using microwave bands and millimeter wave bands.Generally,this work can give an insight into the design and optimization of THz communication systems for 6G.

Environmental Issues of Geothermal Development in Yangbajing, Tibet and the Countermeasures

The pollution source and pollution state of surface water is respectively assessed with equal-standard-pollution-load index and Nemero index, and the habitans' health is assessed as well by comparison with pre-development of geo-thermal field. Results show that: 1) Three pollutive factors obviously fail to attain the required standards and their order sorted by impact degree is As>F- >S2-. 2) The Nemero index of Donggua cross section of Duilongqu River is 0. 725 and the water quality is at mildly-polluted level. 3) In Lhasa River, the Nemero indexes of cross sections affected by geo-thermal fields are much higher than that of the unaffected one, which shows the present and potential impacts of geo-thermal development. 4) Much more inhabitants nearby got trichomadesis sickness after geothermal development, which shows that the surface water pollution in this area has threatened the inhabitants' health. In addition, other environmental issues caused by Yangbajing geothermal development are analyzed and some countermeasures are proposed.

Path loss modelling and comparison based on the radio propagation measurement at 3.5GHz

Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bands due to a relatively large capacity available. Thus, Measurement and modelling methods of radio propaga- tion eharaeteristics are proposed for the field test of Chinese 4th generation （4G） trial system. The mea- surement system is established for 3.5GHz based on the sophistieated measurement instruments and the virtual instrument teehnology. The characteristic parameters of radio propagation sueh as path loss （PL） exponent and shadow fading standard deviation are extracted from measurement data, which result in the path loss model finally. The comparisons with other existing international models results validate our mea- surement in terms of path loss model. Based on the analysis of the existing extension model assumed for the microwave frequency at 3.5GHz, we find that the Stanford University Interim （SUI） model fits very well with the measurement result in the hotspot scenario, while the COST 231 model is closer to the mea- surement result in the suburban scenario. This result provides a measurement-based channel referenee for the development of the future IMT-Advanced systems in China.

Predicament and Countermeasure Analysis of Intellectual Property Management for Strategic Emerging Industry

Intellectual property is the core support and important driving force for the sound development of strategic emerging industry. This paper makes an analysis on the current predicament of intellectual property management for strategic emerging industry from the four stages of the process,including creation and development management,business management,revenue management and disposal management on intellectual property,and finally explores the solutions and gives some countermeasures.

A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality

Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.

A Measure Theoretical Approach for Path Planning Problem of Nonlinear Control Systems

This paper presents a new approach to find an approximate solution for the nonlinear path planning problem. In this approach, first by defining a new formulation in the calculus of variations, an optimal control problem, equivalent to the original problem, is obtained. Then, a metamorphosis is performed in the space of problem by defining an injection from the set of admissible trajectory-control pairs in this space into the space of positive Radon measures. Using properties of Radon measures, the problem is changed to a measure-theo- retical optimization problem. This problem is an infinite dimensional linear programming (LP), which is approximated by a finite dimensional LP. The solution of this LP is used to construct an approximate solution for the original path planning problem. Finally, a numerical example is included to verify the effectiveness of the proposed approach.

Atom interferometers with weak-measurement path detectors and their quantum mechanical analysis

According to the orthodox interpretation of quantum physics, wave-particle duality(WPD) is the intrinsic property of all massive microscopic particles. All gedanken or realistic experiments based on atom interferometers(AI) have so far upheld the principle of WPD, either by the mechanism of the Heisenberg’s position-momentum uncertainty relation or by quantum entanglement. In this paper, we propose and make a systematic quantum mechanical analysis of several schemes of weak-measurement atom interferometer(WM-AI) and compare them with the historical schemes of strongmeasurement atom interferometer(SM-AI), such as Einstein’s recoiling slit and Feynman’s light microscope. As the critical part of these WM-AI setups, a weak-measurement path detector(WM-PD) deliberately interacting with the atomic internal electronic quantum states is designed and used to probe the which-path information of the atom, while only inducing negligible perturbation of the atomic center-of-mass motion. Another instrument that is used to directly interact with the atomic center-of-mass while being insensitive to the internal electronic quantum states is used to monitor the atomic centerof-mass interference pattern. Two typical schemes of WM-PD are considered. The first is the micromaser-cavity path detector, which allows us to probe the spontaneously emitted microwave photon from the incoming Rydberg atom in its excited electronic state and record unanimously the which-path information of the atom. The second is the optical-lattice Bragg-grating path detector, which can split the incoming atom beam into two different directions as determined by the internal electronic state and thus encode the which-path information of the atom into the internal states of the atom. We have used standard quantum mechanics to analyze the evolution of the atomic center-of-mass and internal electronic state wave function by directly solving Schr¨odinger’s equation for the composite atom-electron-photon system in these WM-AIs. We have also compared our analysis with the theoretical and experimental studies that have been presented in the previous literature. The results show that the two sets of instruments can work separately, collectively, and without mutual exclusion to enable simultaneous observation of both wave and particle nature of the atoms to a much higher level than the historical SM-AIs, while avoiding degradation from Heisenberg’s uncertainty relation and quantum entanglement. We have further investigated the space–time evolution of the internal electronic quantum state, as well as the combined atom–detector system and identified the microscopic origin and role of quantum entanglement, as emphasized in numerous previous studies. Based on these physics insights and theoretical analyses, we have proposed several new WM-AI schemes that can help to elucidate the puzzling physics of the WPD of the atoms. The principle of WM-AI scheme and quantum mechanical analyses made in this work can be directly extended to examine the principle of WPD for other massive particles.

Simultaneous Measurement of Fringe Visibility and Path Predictability of Wave-Particle Duality

An experimental scheme to simultaneously obtain the information of fringe visibility and path predictability is designed. In a modified Young＇s double-slit experiment, two density filters rotating at different frequencies are placed before the two pineholes to encode path information. The spatial and temporal distributions of the output provide us with the wave and particle information of the single photons, respectively. The simultaneous measurement of the wave and particle information inevitably disturbs the system and thus causes some loss of the duality information, which is equal to the mixedness of the photonic state behind the density filters.

The Opening of China's Securities: Challenge, Opportunities and Counter Measures

No matter what is the outcome,as long as China is linked with theworld economy and enjoys thebenefits brought about by variouscountries that have opened theirsecurities market, China’s securities market will open sooner or later.

Emulation of Realistic Multi-Path Propagation Channels inside an Anechoic Chamber for Antenna Diversity Measurements

As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. This paper aims to emulate realistic multi-Path propagation channels in terms of angles of arrivals (AoA) and cross-polarization ratio (XPR) with Rayleigh fading, inside an anechoic chamber, for antenna diversity measurements. In this purpose, a practical multi-probe anechoic chamber measurement system (MPAC) with 24 probe antennas (SATIMO SG24) has been used. However, the actual configuration of this system is not able to reproduce realistic channels. Therefore, a new method based on the control of the SG24 probes has been developed. At first time, this method has been validated numerically through the comparison of simulated and analytical AoA probability density distributions. At the second time, the performance of an antenna diversity system inside the SG24 has been performed in terms of the correlation coefficient and diversity gain (DG) using an antenna reference system. Simulated and measurements results have shown a good agreement.

基于Measurement Studio的人体平衡功能测试分析软件设计

提出了一种基于Measurement Studio的平衡功能测试分析虚拟仪器系统。系统通过压力平板采集重心轨迹信息经USB输送到计算机。通过Measurement Studio和VC++的混合编程,实现重心轨迹实时显示及评定结果的数值显示,并利用VC++和Measurement Studio的兼容性扩展控件功能,提供了多种图形化手段显示和分析评定结果参数,从而得出平衡功能障碍的评估。

Field trial measurement and channel modeling for reconfigurable intelligent surface

With the advantage of programmable electromagnetic properties,Reconfigurable Intelligent Surfaces(RISs)havedrawn wide attention from both industry and academia.RIS-assisted communication systems can promote hugewireless channel quality improvement and remarkable coverage enhancement.This paper proposes generalpathloss model,radiation pattern and mirror beam effect of 1-bit RIS at sub-6 GHz band.Field trails have beencarried out in outdoor and indoor deployment scenarios.The proposed model is validated through extensivesimulations and field-trial measurements.In addition,an optimized RIS phase-shit design process for the mirrorbeam elimination is proposed and validated with simulations.The proposed theoretical model and measurementresults can promote future research and application in RIS-assisted communications.

Simultaneous Measurements of Coal Ash Composition by Laser-induced Breakdown Spectroscopy in Different Optical Collection

针对燃煤组分分布不均匀的特性，研究不同收光模式对激光诱导击穿光谱技术同步测量灰成分的影响。选用具有不同灰成分含量梯度的燃煤样品作为检测对象，对比分析同向收光和侧向收光下灰成分组成元素谱线信号探测的强度和稳定性及SiO2、Al2O3、Fe2O3、CaO、MgO和TiO2含量定量分析的精确度。研究结果表明，相同实验条件下同向收光模式的光谱信号稳定性和定量分析精确度更好，检验样品中各灰成分的预测值和参考值之间的拟合度均在0．986以上。而侧向收光模式下探测到的光谱信号强度更强，光谱探测下限可以达到190nm。

A BI4π COUNTING METHOD FOR THE MEASUREMENT OF ACTIVITY

In this article, a Bi4π counting method comprised of Bi4πcounter and a new fundamental measurement method was described, which can measures rather more radionuclides and can achieve accuracy of 0.03% to 0.06% (1σ), in principle. Thecorrectness of this method is demonstrated by measurements of 60Co sources which results of activities compared with 47πβ-γ coincident method are in agreement within the measurement errors, and it is readily achieved to accuracy of 0.2%. Finally, the range of the applications for this Bi4π counting method among one hundred or more important radionuclides is also discussed.

Improved sample filtering method for measuring end-to-end path capacity

By analyzing the effect of cross traffic (CT) enforced on packet delay, an improved path capacity measurement method, pcapminp algorithm, was proposed. With this method, path capacity was measured by filtering probe samples based on measured minimum packet-pair delay. The measurability of minimum packet-pair delay was also analyzed by simulation. The results show that, when comparing with pathrate, if the CT load is light, both pcapminp and pathrate have similar accuracy; but in the case of heavy CT load, pcapminp is more accurate than Pathrate. When CT load reaches 90%, pcapminp algorithm has only 5% measurement error, which is 10% lower than that of pathrate algorithm. At any CT load levels, the probe cost of pcapminp algorithm is two magnitudes smaller than that of pathrate, and the measurement duration is one magnitude shorter than that of pathrate algorithm.

Measurements and analysis at 400MHz and 2600MHz in corridor radio channel

A propagation measurement campaign was performed at the 10 th floor corridor of Xingjian Building,Shanghai University,China.The channel was sounded by pseudo noise( PN) sequence at carrier frequencies of 400-and 2600-MHz respectively.In order to obtain large scale and small scale propagation characteristics in the corridor,the receiver was moved along the corridor every 1.02 meter to record the impulse response.More than 280,000 impulse responses were recorded in the campaign.This work first describes the principle of the measurement,and then how the recorded raw data are processed.The results show that path loss exponent is related to frequency.The relationship between the root-mean squared( RMS) delay spread and the T-R separation distance is analyzed.The RMS delay spread and the mean excess delay spread against path loss are also given,which explain why the 2600 MHz RMS delay spread is larger than that of 400 MHz.

Dust particles in free troposphere over Chinese desert region revealed from balloon borne measurements under calm weather conditions

The Taklamakan Desert in China is one of the major source regions for Asian dust particles.All balloon-borne measurements in this report were carried out in Dunhuang,in the Taklamakan Desert,during calm weather conditions.The aerosol number concentration,size distribution,mass concentration,and horizontal mass flux due to westerly wind were investigated.The measurements were performed on 17 August 2001,17 October 2001,11 January 2002,and 30 April 2002.Five channels(0.3,0.5,0.8,1.2,and 3.6μm in diameter)were used in the Optical Particle Counter for particle measurements.The aerosol number concentration in the winter season(11 January 2002)at 3–5 km was very high.Variation of free-tropospheric aerosols on 30 April 2002 was noticeable.A super-micron range was noticeable in the size distribution of all the measurements.Many variations in temperature and aerosol concentration were found at these inversion points.High values of estimated mass concentration of aerosols were frequently observed in the atmosphere near the ground(i.e.,1–2 km);and interestingly,relatively high concentrations were frequently detected above 2 km from the surface.Wind patterns observed using ERA-Interim data at 500 and 850 hPa showed that westerly winds dominated in the Taklamakan Desert during the observation period.The average horizontal mass flux of background Asian dust due to westerly wind was observed to fall within the range of 58.5–1219 tons km?2 d?1.Vertical profiles of aerosol number concentrations showed that significant transport of aerosols dominated in the westerly region(i.e.,4–7 km).