Professor Len Tyler

Fall 2000-2001

Date: Wednesday, November 8, 2000
Time: 4:15-5:30 PM; Refreshments at 4:00 PM
Location: 380-380Y

Integrated Resource Allocation and Adaptive Antennas in TDMA Cellular Systems with Mobility

Shin-shiuan Cheng
Electrical Engineering, Stanford University


Wireless personal communications is one of the fastest growing fields in recent years. It has captured a lot of attention of the media, and with that, the imagination of the general public. First-generation analog together with second-generation digital cellular systems offer widespread coverage and a multitude of services. Currently, plans are under way for third-generation systems, which are envisioned as a hybrid mixture of indoor, low-tier and high-tier networks covering both pedestrian and vehicular environments, as well as mobile satellite systems reaching the most remote locations. They promise to provide a wide range of services anywhere and anytime.

This ever-increasing popularity of mobile wireless communication services has motivated the need for increased capacity on a per-channel per-base-station basis. In the context of FDMA/TDMA systems, a fundamental limitation on the capacity is the mutual interference among co-channel users. Co-channel interference can be reduced or controlled through efficient and prudent allocation of system channel and power resources and incorporating adaptive antennas.

In this talk, we will start with a brief introduction of the current research activities in Wireless Research Group at Stanford lead by Prof. D. C. Cox. Then we will give a short tutorial on wireless channel modeling, followed by discussion of Channel Allocation, Power Control and Adaptive Antennas techniques and how each of them combats co-channel interference while working separately. We then show the capacity and system performance gain, through large-scale intensive computer simulation, achieved by the integrated use of these techniques. We quantify the benefit (in terms of Grade of Service (GOS), power saving and handoff rate reduction) and address some system design tradeoffs. From our simulation result, we conclude that significant gain can be attained by integrating resource allocation and adaptive antennas in cellular communications systems.

Shin-shiuan Cheng received B.S. degree from National Taiwan University and M.S. degree from Stanford University. He is currently a Ph.D. student in Wireless Research Group at Stanford University