조광제어를 고려한 MIMO-VLC 시스템의 전력 효율 분석

국문 초록 (Abstract)

백색 발광다이오드(LEDs)는 형광등보다 경제적이며 높은 밝기, 수명, 내구성을 제공한다. 이러한 LED는 사람들의 일상생활과 밀접하게 연결되어 있기 때문에 LED의 조광제어는 에너지 절약과 삶의 질 향상에 중요한 요소이다. 이 LED를 사용하는 가시광통신시스템에서는 안테나 수에 비례해 채널 용량을 확보할 수 있다는 점에서 복수의 MIMO(입력 다중 출력) 기술이 많은 관심을 끌었다. 본 논문은 가시광통신(VLC) 시스템에서 적용된 공간-시간 블록 코드(STBC) 기법의 세 가지 변조의 전력 성능을 분석한다. 변조 방식은 RZ-OOK(Return-to-On-Ok), 가변 펄스 위치 변조(VPPM), 중첩 펄스 위치 변조 (OPPM) 및 조광 제어를 적용하였다. 전력 요구사항과 전력 소비는 세 가지 종류의 변조 하에서 2 × 2 STBC-VLC 환경에서 전력 효율을 비교하는 지표로 사용되었다. 조광 제어가 각 변조 체계의 통신 성능에 영향을 미치는지 확인하였다. 확인 결과 VPPM은 세 가지 변조 중 소비량이 더 많았으며 OPPM은 VPPM에 비해 에너지 절감 효과를 보였다.

다국어 초록 (Multilingual Abstract)

White light-emitting diodes (LEDs) are more economical than fluorescent lights, and provide high brightness, a high lifetime expectancy, and greater durability. As LEDs are closely connected with people’s daily lives, dimming control of LED is an important component in providing energy savings and improving quality of life. In visible light communications systems using these LEDs, multiple input multiple output (MIMO) technology has attracted a lot of attention, in that it can attain the channel capacity in proportion to the number of antennas. This paper analyzes the power performance of three kinds of modulation in visible light communications (VLC) systems applied space-time block code (STBC) techniques. The modulation schemes are return-to-zero on-off keying (RZ-OOK), variable pulse position modulation (VPPM), and overlapping pulse position modulation (OPPM), and dimming control was applied. The power requirements and power consumption were used as metrics to compare the power efficiency in 2ｘ2 STBC-VLC environments under the three kinds of modulation. We confirm that dimming control affects the communications performance of each modulation scheme. VPPM showed greater consumption among the three modulations, and OPPM showed energy savings comparable to VPPM.

목차 (Table of Contents)

• 요약
• Abstract
• Ⅰ. Introduction
• Ⅱ. System Model
• Ⅲ. Analysis of Power Efficiency in STBC-VLC Systems
• 1. Modulation Scheme for Dimming Control
• 2. Analysis of Power Requirements
• 3. Analysis of Power Consumption
• Ⅳ. Simulation Results and Analysis
• Ⅴ. Conclusion
• References

참고문헌 (Reference)

1 J. M. Kahn, "Wireless infrared communications" 85 (85): 265-298, 1997

2 Xiaodong Wang, "Wireless Communication Systems: Advanced Techniques for Signal Reception" Pearson Education (Asia)Pte. Ltd 2004

3 Aleksandar Jovicic, "Visible light communication: opportunities, challenges and the path to market" Institute of Electrical and Electronics Engineers (IEEE) 51 (51): 26-32, 2013

4 Mohsen Kavehrad, "Sustainable energy-efficient wireless applications using light" Institute of Electrical and Electronics Engineers (IEEE) 48 (48): 66-73, 2010

5 Thilo Fath, "Performance Comparison of MIMO Techniques for Optical Wireless Communications in Indoor Environments" Institute of Electrical and Electronics Engineers (IEEE) 61 (61): 733-742, 2013

6 Z. Ghassemlooy, "Optical Wireless Communications. System and Channel Modelling with MATLAB" Taylor & Francis Group 2013

7 Kwonhyung Lee, "Modulations for Visible Light Communications With Dimming Control" Institute of Electrical and Electronics Engineers (IEEE) 23 (23): 1136-1138, 2011

8 H. Park, "Modulation analysis for wireless infrared communications" 2 : 1182-1186, 1995

9 J.B. Carruthers, "Modeling of nondirected wireless infrared channels" Institute of Electrical and Electronics Engineers (IEEE) 45 (45): 1260-1268, 1997

10 Tsung-Hui Chang, "Maximum-Likelihood Detection of Orthogonal Space-Time Block Coded OFDM in Unknown Block Fading Channels" Institute of Electrical and Electronics Engineers (IEEE) 56 (56): 1637-1649, 2008

11 T. Ohtsuki, "Lower bounds on capacity and cutoff rate of differential overlapping pulse position modulation in optical direct-detection channel" 77 : 1230-1237, 1994

12 A. B. Siddique, "Joint brightness control and data transmission for visible light communication systems based on white LEDs" 1026-1030, 2011

13 Wondae Kim, "Industry and Technology trend Analysis of Visible Light Communication (VLC)" 2011

14 Hany Elgala, "Indoor optical wireless communication: potential and state-of-the-art" Institute of Electrical and Electronics Engineers (IEEE) 49 (49): 56-62, 2011

15 "IEEE standard for local and metropolitan area networks. Part 15.7: Short-Range Wireless Optical Communication using Visible Light"

16 Sridhar Rajagopal, "IEEE 802.15.7 visible light communication: modulation schemes and dimming support" Institute of Electrical and Electronics Engineers (IEEE) 50 (50): 72-82, 2012

17 L. Halonen, "Guidebook on energy efficient electric lighting for buildings" Dept. Electron. Lighting Unit, Aalto Univ. School Sci. Technol 2010

18 T. Komine, "Fundamental analysis for visible-light communication system using LED lights" Institute of Electrical and Electronics Engineers (IEEE) 50 (50): 100-107, 2004

19 徐至展 徐至展, "Efficient user access and lamp selection in LED-based visible light communication network" Shanghai Institute of Optics and Fine Mechanics 10 (10): 050602-50606, 2012

20 J. Garcia, "Dimming of High-Brightness LEDs by Means of Luminous Flux Thermal Estimation" Institute of Electrical and Electronics Engineers (IEEE) 24 (24): 1107-1114, 2009

21 Jelena Grubor, "Broadband Information Broadcasting Using LED-Based Interior Lighting" Institute of Electrical and Electronics Engineers (IEEE) 26 (26): 3883-3892, 2008

22 Q. Wang, "Asymmetrical hybrid optical OFDM for visible light communications with dimming control" 27 (27): 974-977, 2015

23 R. Klemm, "Applications of Space-Time Adaptive Processing" IEE 2004

24 V. Jungnickel, "A physical model of the wireless infrared communication channel" Institute of Electrical and Electronics Engineers (IEEE) 20 (20): 631-640, 2002

25 Dobroslav Tsonev, "A 3-Gb/s Single-LED OFDM-Based Wireless VLC Link Using a Gallium Nitride $\mu{\rm LED}$" Institute of Electrical and Electronics Engineers (IEEE) 26 (26): 637-640, 2014

26 Y. Wang, "875-Mb/s asynchronous bi-directional 64QAM-OFDM SCM-WDM transmission over RGB-LED-based visible light communication system" 1-3, 2013

27 "802.15.7 PHY and MAC Standard for Short Range Wireless Optical Communication Using Visible Light, IEEE Std."