Project: IEEE P Working Group for Wireless Personal Area Networks N

Transcription

1 Project: IEEE P Working Group for Wireless Personal Area Networks N (WPANs( WPANs) Title: [VLC channel measurement in indoor application] Date Submitted: [10 July, 2008] Source: [(1)Atsuya Yokoi, Jaeseung Son] Company [(1)Samaung Yokohama Research ] Address [(1)2-7, Sugasawa-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, Japan] Voice:[(1) ], FAX: [(1) ], [(1)atsuya.yokoi@samsung.com] Re: [] Abstract: [The overview of the visible light communication (VLC) channel measurement and its measured results. The measured impulse responses are compared with the simulation results.] Purpose: [Contribution to IEEE SG-VLC] Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P Slide 1

2 VLCchannel measurement in Indoor applications Samsung Electronics Slide 2

3 Contents Introduction VCL channel measurement system System configuration Principle of impulse response measurement Measurement environment & scenario VLC channel measurement results PN code corelation Impulse response Conclusion Slide 3

4 Introduction Samsung presented VLC channel modeling simulation in the previous meeting. It showed the impulse response results at indoor environment. We had some light propagation measurements for confirming the validity of the simulation. Simulation Model Impulse Response Slide 4

5 Measurement system configuration Tx Module φ7cm lens Rx Module Pulse Gen. PN code 300MHz D LED Path PD I/V Sampling Osciloscope (2Gsample/s) EDL300E (650nm) PN strobe EDL300D Data Up Load Correlation Analysis (MATLAB) PC RC LED and PIN-PD are used for high speed modulation PN (Pseudo-Noise) code is sent from Txwith 300MHz code rate Received data is sampled by Osciloscope and analyzed on PC PN strobe is used for timing synchronization Slide 5

6 Principleof Impulse responsemeasurement 0.1 PN300M 1 cm.xls Correlation (Ave.) Wave form of received PN code time [ns] Correlation with PN code Impulse response is obtained by calculating the corelation with PN code. The resolution of impulse response is 3.3nS at 300MHz PN code rate. PN code: M sequence (Length : 127, Period : 423nS) Slide 6

7 Measurement Environment 465cm Wall B Curtain Diffuse 100 Wall C (Cloth Diffuse) Position B Ceiling height: 350cm Wall D Cloth Diffuse Position A Tx(100, 75, 220) Rx(100, 65, 90) Position B Tx(100, 155, 220) Rx(100, 145, 90) [cm] [cm] Position A Wall A Wood coated with varnish Glossy/Specular Reflection Reflection index : around 8% 745cm Slide 7

8 Measurement Scenario Wall A 75 or 155 Tx Reflection Path Direct Path Rx or Desk The angles of Tx, Rx are adjusted for measuring the each propagation path. Slide 8

9 Directed Light 0.09 PN300M T 220R90 D 0.xls Correlation (Ave.) time [ns] Wave form of received PN code Correlation with PN code Position A Tx (100, 75, 220), Rx(100, 65, 90) PN (300MHz, 127) Slide 9

10 Reflected Light 7 x 10-3 PN300M T 220R90 R 70L.xls Correlation (Ave.) time [ns] Wave form of received PN code Correlation with PN code Position A Tx (100, 75, 220), Rx(100, 65, 90) PN (300MHz, 127) Slide 10

11 Impulse response Position A Impulse response Direct path Reflection path Simulation Impulse response Direct path Reflection path Simulation Power [W] Power [dbm] Delay time [ns] Delay time [ns] Tx (100, 75, 220), Rx(100, 65, 90), PN (300MHz, 127) Delay time of the Reflected light from the Directed light : 2.6nS Power ratio of the Reflected light to the Direct light : -18.5dB Slide 11

12 Impulse response -Position B Impulse response Direct path Reflection path Simulation Impulse response Direct path Reflection path Simulation Power [W] Power [dbm] Delay time [ns] Delay time [ns] Tx (100, 155, 220), Rx(100,145, 90), PN (300MHz, 127) Delay time of the Reflected light from the Directed light : 7.3nS Power ratio of the Reflected light to the Direct light : -21.1dB Slide 12

13 Conclusion We had the light propagation measurement for obtaining the impulse response in indoor environment. The measured impulse responses had good agreements with the simulation. We can say the simulation is useful for expecting the light propagation in indoor environment. Slide 13

14 Appendix Environmen t size Tx height Rx height # of Tx and Position FOV (Device) TX power etc 7.45m x 4.65m x 3.5m(H) 2.2m 0.9m 1 (100,75,220) or Tx: ±70 (±10 ) Rx: EDL300 E 0.5mW EDL300D PD size: Φ7mm lens and φ70mm lens (100,155,220) ±70 (±10 ) Wall A Reflection Index:8% Measurement Conditions Slide 14

15 Photon model Trace the light path Photon Model Quantum theory Ray tracing Computer simulation tool RF channel modeling method Slide 15

16 Reflection Type Diffuse Rough surface Clothing, paper and asphalt road Lambertian reflection Mirror/Specular Smooth surface Mirror or calm water Reflection Index Glossy/Specular Not diffuse,mirror BRDF(Bidirectiona l Reflectance Distribution Function) Slide 16

17 Impulse response comparison (a) Prof. Nakagawa (b) Samsung Slide 17