Design of an Omnidirectional Multibeam Transmitter for High-Speed Indoor Wireless Communications
- PDF / 3,423,647 Bytes
- 12 Pages / 600.05 x 792 pts Page_size
- 22 Downloads / 184 Views
Research Article Design of an Omnidirectional Multibeam Transmitter for High-Speed Indoor Wireless Communications Jaw-Luen Tang and Yao-Wen Chang Department of Physics, National Chung Cheng University, Chiayi County 62102, Taiwan Correspondence should be addressed to Jaw-Luen Tang, [email protected] Received 30 October 2009; Revised 17 April 2010; Accepted 9 May 2010 Academic Editor: Anthony C. Boucouvalas Copyright © 2010 J.-L. Tang and Y.-W. Chang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. For future high speed indoor wireless communication, diffuse wireless optical communications offer more robust optical links against shadowing than line-of-sight links. However, their performance may be degraded by multipath dispersion arising from surface reflections. We have developed a multipath diffusive propagation model capable of providing channel impulse responses data. It is aimed to design and simulate any multibeam transmitter under a variety of indoor environments. In this paper, a multi-beam transmitter system associated with hemisphere structure is proposed to fight against the diverse effects of multipath distortion albeit, at the cost of increased laser power and cost. Simulation results of multiple impulse responses showed that this type of multi-beam transmitter can significantly improve the performance of BER suitable for high bit rate application. We present the performance and simulation results for both line-of-sight and diffuse link configurations. We propose a design of power radiation pattern for a transmitter in achieving uniform and full coverage of power distributions for diffuse indoor optical wireless systems.
1. Introduction In recent years, the development of indoor optical wireless communication system has received great attention due to its capability for future high speed and flexible optical communications at low cost [1–11]. Wireless optical link can also offer a secure and a promising alternative to radio communications for wireless indoor applications. Indoor optical wireless network (such as Infrared links) can be classified as several configurations for link design. In simple infrared links the classification is normally based on the directionality and line-of-sight (LOS) between the receiver and transmitter [7, 8]. In LOS link system, optical carrier from the transmitter reaches the receiver directly, while in non-LOS link system, an optical carrier reaches the receiver after some diffusive reflections by the ceiling and/or walls in the room. Directed LOS links are the most widely used IR links and offer low path loss, but require precise alignment of the transmitter/receiver and are susceptible to blockage of the beams. Nondirected non-LOS links, also known as diffuse links, where the optical carrier is reflected diffusively to omnidirection and fills the whole room can
avoid the need for aiming the transmitter and provide r
Data Loading...
