P427.1 2004032369 气悬体对远红外入射波的衰减研究=Study of the far IRincident wave attenuation by the aerosol[刊,中]/陈治平(解放军炮兵学院一系侦察通信室.安徽,合肥(230037)),许自富…∥光电技术应用.—2003,18(4).—1-3,25 ...P427.1 2004032369 气悬体对远红外入射波的衰减研究=Study of the far IRincident wave attenuation by the aerosol[刊,中]/陈治平(解放军炮兵学院一系侦察通信室.安徽,合肥(230037)),许自富…∥光电技术应用.—2003,18(4).—1-3,25 研究了多种物质的远红外传输性能,通过计算单个粒子的有关参数,导出了一定条件下气悬体粒子随参量变化时的透射关系。展开更多
The key techniques in indoor positioning based on visible light communication and the state of the art of this research were surveyed. First, the significance of indoor positioning based on visible light communication...The key techniques in indoor positioning based on visible light communication and the state of the art of this research were surveyed. First, the significance of indoor positioning based on visible light communication from two aspects of the limitations of current indoor positioning technology and the advantages of visible light communication was discussed; And then, the main four technology of indoor positioning based on visible light communication were summarized and the triangulation of RSS method and the principle of image positioning were introduced in detail; Next, the performance characteristics of various typical algorithms were compared and analyzed; In the end, several suggestions on future research of indoor positioning based on visible light communication were given.展开更多
It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a signific...It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a significant issue for wireless communication networks with massive antennas and ultra-dense cell. This paper proposes a learning- based channel model, which can estimate, refine, and manage CSI for a synergetic transmission system. It decomposes the channel impulse response into multiple paths, and uses a learning-based algorithm to estimate paths' parameters without notable degradation caused by sparse pilots. Both indoor measurement and outdoor measurement are conducted to verify the feasibility of the proposed channel model preliminarily.展开更多
Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmissio...Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmission due to the modulation nonlinearity of LED.In order to solve this problem,a scheme by separating the LEDs for the functions of dimming control and data transmission respectively is proposed in this paper.In the scheme,the LEDs used for dimming control function are driven by a dc amplified circuit,and the LEDs for data transmission are driven by a digital modulation circuit respectively.In this way,the modulation distortion to the data signal caused by the modulation nonlinearity can be avoided even if the dimming is at high level dc driven current.The proof-of-concept experiment of a 2.5Mbit/s visible light communication system demonstrates that the dimming controlling and data transmission can be realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function.Compared to previous methods,the scheme in this paper is simpler and cost effective,and makes sense when high rate data is transmitted in a visible light communication system.展开更多
Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communicatio...Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communications.Based on the propagation and signal modulation characteristics of visible light,a link model for the indoor wireless visible light communications is established.Using the model,three channel estimation methods,i.e.,the correlation method,the least square(LS) method and the minimum mean square error(MMSE) method,are proposed.Moreover,the performances of the proposed three methods are evaluated by computer simulation.The results show that the performance of the correlation method is the worst,the LS method is suitable for higher signal to noise ratio(SNR),and the MMSE method obtains the best performance at the expense of highest complexity.展开更多
A location-adaptive transmission scheme for indoor visible light communication(VLC) system is proposed in this paper.In this scheme,the symbol error rate(SER) of less than 10-3 should be guaranteed.And the scheme is r...A location-adaptive transmission scheme for indoor visible light communication(VLC) system is proposed in this paper.In this scheme,the symbol error rate(SER) of less than 10-3 should be guaranteed.And the scheme is realized by the variable multilevel pulse-position modulation(MPPM),where the transmitters adaptively adjust the number of time slots n in the MPPM symbol according to the position of the receiver.The purpose of our scheme is to achieve the best data rate in the indoor different locations.The results show that the location-adaptive transmission scheme based on the variable MPPM is superior in the indoor VLC system.展开更多
文摘P427.1 2004032369 气悬体对远红外入射波的衰减研究=Study of the far IRincident wave attenuation by the aerosol[刊,中]/陈治平(解放军炮兵学院一系侦察通信室.安徽,合肥(230037)),许自富…∥光电技术应用.—2003,18(4).—1-3,25 研究了多种物质的远红外传输性能,通过计算单个粒子的有关参数,导出了一定条件下气悬体粒子随参量变化时的透射关系。
基金supported by National Nature Science Foundation of China (No. 61373124)supported by China Scholarship Funds (2014CB3033)
文摘The key techniques in indoor positioning based on visible light communication and the state of the art of this research were surveyed. First, the significance of indoor positioning based on visible light communication from two aspects of the limitations of current indoor positioning technology and the advantages of visible light communication was discussed; And then, the main four technology of indoor positioning based on visible light communication were summarized and the triangulation of RSS method and the principle of image positioning were introduced in detail; Next, the performance characteristics of various typical algorithms were compared and analyzed; In the end, several suggestions on future research of indoor positioning based on visible light communication were given.
基金supported by National Basic Research Program of China (NO 2012CB316002)China’s 863 Project (NO 2014AA01A703)+2 种基金National Major Projec (NO. 2014ZX03003002-002)Program for New Century Excellent Talents in University (NCET-13-0321)Tsinghua University Initiative Scientific Research Program (2011THZ02-2)
文摘It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a significant issue for wireless communication networks with massive antennas and ultra-dense cell. This paper proposes a learning- based channel model, which can estimate, refine, and manage CSI for a synergetic transmission system. It decomposes the channel impulse response into multiple paths, and uses a learning-based algorithm to estimate paths' parameters without notable degradation caused by sparse pilots. Both indoor measurement and outdoor measurement are conducted to verify the feasibility of the proposed channel model preliminarily.
基金financially supported by National Natural Science Foundation of China(No.61475094)National 973 Program of China(No.2013CB329202)
文摘Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmission due to the modulation nonlinearity of LED.In order to solve this problem,a scheme by separating the LEDs for the functions of dimming control and data transmission respectively is proposed in this paper.In the scheme,the LEDs used for dimming control function are driven by a dc amplified circuit,and the LEDs for data transmission are driven by a digital modulation circuit respectively.In this way,the modulation distortion to the data signal caused by the modulation nonlinearity can be avoided even if the dimming is at high level dc driven current.The proof-of-concept experiment of a 2.5Mbit/s visible light communication system demonstrates that the dimming controlling and data transmission can be realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function.Compared to previous methods,the scheme in this paper is simpler and cost effective,and makes sense when high rate data is transmitted in a visible light communication system.
基金supported by the National Natural Science Foundation of China(No.60972023)the National Science and Technology Important Special Project(Nos.2010ZX03003-002 and 2010ZX03003-004)+4 种基金the Open Research Fund of National Mobile Communication Research Laboratory,Southeast University(No.2010D01)the Open Research Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks,China(No.2008SH06)the Startup Fund of Nanjing University of Aeronautics and Astronautics(NUAA)the NUAA Research Funding(No.NS2010091)the Fundation of Graduate Innovation Center in NUAA
文摘Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communications.Based on the propagation and signal modulation characteristics of visible light,a link model for the indoor wireless visible light communications is established.Using the model,three channel estimation methods,i.e.,the correlation method,the least square(LS) method and the minimum mean square error(MMSE) method,are proposed.Moreover,the performances of the proposed three methods are evaluated by computer simulation.The results show that the performance of the correlation method is the worst,the LS method is suitable for higher signal to noise ratio(SNR),and the MMSE method obtains the best performance at the expense of highest complexity.
基金supported by the Jinlin Provincial Science&Tenchology Department of China(No.20130413052GH)
文摘A location-adaptive transmission scheme for indoor visible light communication(VLC) system is proposed in this paper.In this scheme,the symbol error rate(SER) of less than 10-3 should be guaranteed.And the scheme is realized by the variable multilevel pulse-position modulation(MPPM),where the transmitters adaptively adjust the number of time slots n in the MPPM symbol according to the position of the receiver.The purpose of our scheme is to achieve the best data rate in the indoor different locations.The results show that the location-adaptive transmission scheme based on the variable MPPM is superior in the indoor VLC system.
