Wireless Systems Laboratory provides research support and education in wireless transmission systems and networks.   Two examples are included below.

Wireless Geophone Networks Channel Modeling

Wireless Geophone Networks 


Channel Modeling

The past decade or so has witnessed tremendous growth in mobile communications due to its ability to provide communications to people on the move. Such mobile links communicate between a fixed i.e. stationary base station and a mobile user. In this sense, the mobility is limited at user end only for all present day mobile radio links. However, future applications and trends portend the need for direct communication between mobile users without need for central base stations in order to provide greater mobility, flexibility and convenience of usage. Such systems are termed mobile-to-mobile (M2M) or doubly mobile systems. They find applications in military as well as commercial arena in form of ad-hoc mobile wireless networks, intelligent vehicle systems and broadband highway communications. To enable design of such systems, our research has focused on study and characterization of radio propagation channels for M2M links. The main issues addressed are:

Multi-polarized antennas have attracted considerable attention as a means for increasing channel capacity and reducing the required antenna spacing through the principle of polarization diversity. Such antennas exploit depolarization and have the potential to double or triple the channel capacity that is achievable with single-polarized antennas. In practice, cellular land mobile radio systems have employed slant polarized array antennas at the base stations to good benefit.  Our research has developed a geometrical theory for depolarization in fixed-to-mobile (F2M) and M2M wireless channels. This novel theory reveals the origin of channel depolarization and provides a mechanism for computing crosspolarization discrimination (XPD). Based on the superposition of polarization components on conservation-of-polarization planes, a three-dimensional (3-D) geometry-based reference model has been developed for determining the observed XPD. This purely theoretical approach can be used to derive the XPD without the aid of measurement data or its approximation. The geometrical theory and reference model provide a relationship between channel depolarization or XPD and channel modeling factors such as the distance between the transmitter and the receiver, the azimuth/elevation angles of arrival and departure, and the distribution of scatterers around the transmitter and/or receiver.  

In recent years, new spectrum allocations in the millimeterwave (mm-wave) bands have driven the development of the fifth-generation (5G) wireless communications, due to the rapidly increasing demands for high data rates. The mm-waves have been used extensively for point-to-point satellite communications, and now receive much attention for commercial communication systems. Current applications of mm-wave communications include wireless backhaul, cellular hotspot coverage, wireless personal area networks, wireless local area networks, sensor networks, etc. Recently, mm-wave mobile-to-mobile (M2M) communications have gained strong momentum, as it enables Gbps communications for the future intelligent transportation systems, where a large number of sensors will be incorporated into vehicles and a huge amount of data needs to be transmitted via wireless communications.  The main issues are: 

Home | About WSL | Director | Personnel | Research | Grants and Projects | Publications | Courses | Wireless on the Web | Help | Feedback | Direction

Home of WSL

More information or problems with this page? Please contact Gordon L. Stüber

This page has been accessed  times since January 14, 2003.
This page was last modified on .
Copyright (C) 1999-2000 WSL, Georgia Tech. All Rights Reserved.