Abstract
Indoor infrared communication systems is one of the possible ways of offering data rates in excess of 100 Mbit/a without the need for wiring. Multiple users can share an infrared channel by code division-multiple access (CDMA) techniques. However, the CDMA system, performance is limited by both background noise and co-channel interference. In this paper we study the use of angle diversity for mitigating the effects of the noise and interference. The system considered uses on-off shift keying modulation with multibeam transmitters and imaging receivers. The overall system performance for different diversity combining techniques is evaluated and compared to a system without diversity. Numerical results for a 2-user CDMA system indicate that signal to noise and interference ratio (SNIR) improvement (over systems with no diversity) of 5 dB is obtained for at least 50% of an ensemble of 10000 sample evaluations. The generalized selection combining (GSC) - a new diversity technique yet to be implemented for infrared systems - offers the best performance even with its reduced complexity.
Original language | English |
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Pages (from-to) | 365-381 |
Number of pages | 17 |
Journal | International journal of infrared and millimeter waves |
Volume | 25 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2004 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Diversity
- Infrared communication
- Optical code-division multiplexing
- Optical wireless