McMaster University, Faculty of Engineering  
Dr. Steve Hranilovic
Research Interests
 


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My primary research focus is on the design of communciation algorithms for wireless optical channels. These optical channels transmit information by modulating and detecting the optical intensity of a laser diode or light-emitting diode. Wireless optical communications provide a high-data rate, low cost, secure link which is free of spectral licensing issues.

My research addresses the modem design problem through theoretical and experimental studies. I develop of communication algorithms, signal processing strategies and information theory to allow for the design of efficient signalling strategies for the wireless optical channel. Additionally, I develop prototype wireless optical links on which practical signalling strategies can be verified and tested under realistic conditions. Several projects that I am currently working on are :


Information Theory, Coding and Communication Theory for Optical Intensity Channels
Coding and Modulation for Optical Intensity Channels Conventional information and communication theories cannot be applied directly to optical intensity channels due to the amplitude constraints of the channel. Some areas in which my research presents new results are:
  • Signal-Space Models for Optical Intensity Channels
  • Shaping and Coding Gain for Optical Intensity Lattice Codes
  • Coded Modulation for Wireless Optical Intensity Channels
  • Channel Capacity of Wireless Optical Channels
  • Optical Intensity Multiple-Subcarrier Modulation

Free-Space Optical (FSO) Communications Optical Channels
My research also concerns the investigation into the design of long-range optical wireless communication systems. My group work on theoretical system design as well as practical proof-of-concept demonstrations. In particular, we currently have a 1.9 km free-space optical link operating at 1.6Gbps connected to high-speed data converters as well as multiple Xilinx Virtex FPGAs. For details visit my group website. Some research directions are:
  • Experimental demonstration of coding/modulation techniques for high speed terrestrial FSO
  • Measurement and modelling of terrestrial FSO links
  • MIMO and diversity techniques for FSO links (theory and experiment)
  • Space inter-satellite laser communications
 Free-Space Optical Communications

Visible Light Communciations (VLC)
Visible Light Communications There is an ongoing trend toward energy-efficient lighting systems. This work leverages the installation of LED light soruces by investigating a dual communications role. Here we consider the use of VLC for broadband content distribution as well as many other applications. Some directions we are currently investigating are:
  • Coding and modulation design for high speed communications
  • MIMO VLC Systems
  • Indoor Localization using LED lighting systems
  • Integration of VLC networks with power line communications
  • Use of visible light communications in automotive applications include vehicle-to-vehical communications and vehicle-to-infrastructure communications
  • Experimental prototype VLC networks


Please consult by publications page for more details regarding my research program.