GLOBECOM 2005 Tutorial

Monday, 28 November
Majestic Ballroom F / Level Two / Renaissance Grand Hote

Title: TU01   Synchronization for WCDMA

Duration: Full Day/9:00AM-5:00PM

Instructor(s):
Ali Ghrayeb, Concordia University, Quebec Canada

Abstract:
Wideband code division multiple access (WCDMA) is being standardized around the world as an air interface technology for the third generation (3G) services. WCDMA has already been deployed in different parts of the world and its deployment is expended to witness tremendous growth in the next few years. One of the main advantages of WCDMA is its ability to provide high data rates and high capacity, all relative to already existing air interface technologies. To harvest these promised improvements, robust synchronization algorithms, which is the focus of this tutorial, must be deployed at the receiver. The synchronization process is normally divided into two main phases: acquisition and tracking. Acquisition is first used to achieve synchronization to within a fraction of the chip duration between the incoming pseudo-noise (PN) code and the locally generated one. Tracking is then used to minimize the timing error and to keep the signals aligned for a long period of time. The tutorial starts with a brief introduction to WCDMA including a summary of its main parameters, differences and similarities between WCDMA and already existing technologies, and the various structures of the transmitter and receiver for the uplink and downlink channels. Various robust code acquisition algorithms will be discussed, including a comparative study between these algorithms in terms of complexity and performance. The tutorial then turns into code tracking in which various tracking algorithms are considered, including adaptive tracking, and coherent versus non-coherent tracking. Furthermore, the tutorial discusses different robust and simple channel estimation techniques of which some are being used in the current air interface technologies. Finger assignment strategies based on signal strength as well as signal-to-interference ratio will also be introduced. In addition, frequency estimation techniques will be considered. For the sake of completeness, the tutorial also touches on power control algorithms and their impact on the overall performance of WCDMA. Some of the algorithms that will be discussed in this tutorial are already in use in today's technologies, and some are novel. Several examples will be discussed throughout the tutorial including cdma2000.

Motivation:
This tutorial addresses a very recent technology which is being standardized around the world. Hence, it is expected to draw a lot of interest from the wireless communications community from different parts of the world. Some of the algorithms to be discussed in this tutorial are already being used in nowadays technologies and some are being under consideration.