Indoor Free-Space Optical Communication

Free-space optics is a promising medium for short-range, indoor wireless communications, offering high bit rates and dense spatial reuse. Our research involves both theoretical and experimental studies. Recent theoretical work has addressed trellis-coded pulse-position modulation, decision-feedback equalization, rate-adaptive coding techniques, and multiple-access techniques. On the experimental front, we have characterized multipath channels, tested several novel optical receiving "antenna" designs, and demonstrated prototype non-line-of-sight communication links operating at bit rates up to 100 Mb/s. We designed a wireless video distribution system for airliner cabins that has an aggregate throughtput of approximately 1 Gb/s.

Review Articles

J.M. Kahn and J. R. Barry, "Wireless Infrared Communications", Proc. of the IEEE, vol. 85, pp. 265-298, February 1997. (Invited Paper). PDF

J.M. Kahn, J. R. Barry, M. D. Audeh, J. B. Carruthers, W. J. Krause, and G. W. Marsh, "Non-Directed Infrared Links for High-Capacity Wireless LANs", IEEE Pers. Commun. Mag., vol. 1, no. 2, pp. 12-25, Second Quarter 1994. (Invited Paper).

Modulation, Coding and Equalization Techniques

R. You and J. M. Kahn, "Average Power Reduction Techniques for Multiple-Subcarrier Intensity-Modulated Optical Signals", IEEE Trans. on Commun., vol. 49, pp. 2164-2171, December 2001. PDF

R. You and J. M. Kahn, "Upper-Bounding the Capacity of Optical IM/DD Channels with Multiple-Subcarrier Modulation and Fixed Bias using Trigonometric Moment Space Method", IEEE Trans. on Info. Theory, vol. 48, pp. 514-523, February 2002. PDF

D. Shiu and J. M. Kahn, "Shaping and Non-Equiprobable Signaling for Intensity Modulated Signals", IEEE Trans. on Information Theory, vol. 45, pp. 2661-2668, November 1999. PDF

D. Shiu and J. M. Kahn, "Differential Pulse-Position Modulation for Power-Efficient Optical Communication", IEEE Trans. on Commun., vol. 47, no. 8, pp. 1201-1210, August 1999. PDF

M.D. Audeh, J. M. Kahn and J. R. Barry, "Decision-Feedback Equalization of Pulse-Position Modulation on Measured Non-Directed Indoor Infrared Channels", IEEE Trans. on Commun., vol. 47, pp. 500-503, April 1999. PDF

L. Diana and J. M. Kahn, "Rate-Adaptive Modulation Techniques for Infrared Wireless Communications", Proc. of IEEE Intl. Conf. on Commun., Vancouver, B.C., Canada, June 6-10, 1999. The version published in the conference proceedings contains some minor typographical errors that are corrected in this version. PDF

D.C. Lee and J. M. Kahn, "Coding and Equalization for PPM on Wireless Infrared Channels", IEEE Trans. on Commun., vol. 47, no. 2, pp. 255-260, February 1999. PDF

D.C. Lee, J. M. Kahn and M. D. Audeh, "Trellis-Coded Pulse-Position Modulation for Indoor Wireless Infrared Communications", IEEE Trans. on Commun., vol. 45, pp. 1080-1087, September 1997. PDF

M.D. Audeh, J. M. Kahn and J. R. Barry, "Performance of Pulse-Position Modulation on Measured Non-Directed Indoor Infrared Channels", IEEE Trans. on Commun., vol. 44, pp. 654-659, June 1996. PDF

J.B. Carruthers and J. M. Kahn, "Multiple-Subcarrier Modulation for Non-Directed Wireless Infrared Communication", IEEE J. Sel. Areas in Commun., vol. 14, pp. 538-546, April 1996. PDF

Diversity Detection Techniques

P. Djahani and J. M. Kahn, "Analysis of Infrared Wireless Links Employing Multi-Beam Transmitters and Imaging Diversity Receivers", IEEE Trans. on Commun., vol. 48, no. 12, pp. 2077-2088, December 2000. PDF

J.M. Kahn, P. Djahani, A. G. Weisbin, K. T. Beh, A. P. Tang and R. You, "Imaging Diversity Receivers for High-Speed Infrared Wireless Communication", IEEE Commun. Mag., vol. 36, no. 12, pp. 88-94, December 1998. PDF

J.B. Carruthers and J. M. Kahn, "Angle Diversity for Nondirected Wireless Infrared Communication", IEEE Trans. on Commun. vol. 48, no. 6, pp. 960-969, June 2000. PDF

A. P. Tang, J. M. Kahn and K.-P. Ho, "Wireless Infrared Communication Links using Multi-Beam Transmitters and Imaging Receivers", Proc. of IEEE Intl. Conf. on Commun., pp. 180-186, Dallas, Texas, June 23-27, 1996. PDF

Multiple-Access Techniques

F. Chow and J. M. Kahn, "Effect of Non-Reciprocity on Infrared Wireless Local-Area Networks", Proc. of IEEE Global Commun. Conf., Rio de Janeiro, Brazil, December 5-9, 1999. PDF   For a more detailed description of this work, see: F. Chow, "Effect of Non-Reciprocity on Infrared Wireless Local-Area Networks", M.S. Report, University of California, Berkeley, December 1998. PDF

G. W. Marsh and J. M. Kahn, "Channel Reuse Strategies for Indoor Infrared Wireless Communications", IEEE Trans. on Commun., vol. 45, no. 10, pp. 1280-1290, October 1997. PDF

Channel Characterization and Modeling

J. B. Carruthers and J. M. Kahn, "Modeling of Nondirected Wireless Infrared Channels", IEEE Trans. on Commun., vol. 45, no. 10, pp. 1260-1268, October 1997. PDF

J. M. Kahn, W. J. Krause and J. B. Carruthers, "Experimental Characterization of Non-Directed Indoor Infrared Channels", IEEE Trans. on Commun., vol. 43, pp. 1 613-1623, April 1995. PDF

J. R. Barry, J. M. Kahn, W. J. Krause, E. A. Lee, and D. G. Messerschmitt, "Simulation of Multipath Impulse Response for Wireless Optical Channels", IEEE J. Sel. Areas in Commun., vol. 11, no. 3, pp. 367-379, April 1993. PDF

Optical Component Design

J. R. Barry and J. M. Kahn, "Link Design for Non-Directed Wireless Infrared Communications", Applied Optics, vol. 34, no. 19, pp. 3764-3776, July 1995. PDF

K.-P. Ho and J. M. Kahn, "Compound Parabolic Concentrators for Narrow-Band Wireless Infrared Receivers", Optical Engineering, vol. 34, no. 5, pp. 1385-1395, May 1995.

Prototype Communication Links

J. B. Carruthers and J. M. Kahn, "Angle Diversity for Nondirected Wireless Infrared Communication", IEEE Trans. on Commun. vol. 48, no. 6, pp. 960-969, June 2000. PDF

D. C. Lee and J. M. Kahn, "Experimental 25-Mb/s Wireless Infrared Link Using 4-PPM with Scalar Decision-Feedback Equalization", Proc. of IEEE Intl. Conf. on Commun., Atlanta, GA, June 7-11, 1998. PDF

G. W. Marsh and J. M. Kahn, "Performance Evaluation of Experimental 50-Mb/s Diffuse Infrared Wireless Link using On-Off Keying with Decision-Feedback Equalization", IEEE Trans. on Commun., vol. 44, no. 11, pp. 1496-1504, November 1996. PDF

G. W. Marsh and J. M. Kahn, "50-Mb/s Diffuse Infrared Free-Space Link using On-Off Keying with Decision-Feedback Equalization", IEEE Photon. Technol. Lett., vol. 6, no. 10, pp. 1268-1270, October 1994. PDF

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Last modified: June 20, 2003.