[CPCC] TALK 6/10/04 Thu 11 AM: Wireless System Design

[Ender Ayanoglu]

Approaches to Wireless Communications Systems Design:
System, Architecture, and Implementation

Dr. Ahmed Eltawil

University of California, Los Angeles

Thursday, June 10, 2004, 11:00AM
Engineering Tower 331

Abstract:

The wireless industry has enjoyed tremendous growth over the past decade
giving rise to a host of wireless applications and services. This fast
paced expansion creates a dilemma for communication system designers who
are driven by two conflicting requirements- increasing complexity to handle
the required QoS and decreasing power consumption to support reasonable
battery lifetime. Only a holistic and systemic approach to the design of
these systems can provide the optimum architecture.

A case study of a WCDMA transceiver is used to illustrate the design
decisions made at the system, architecture and circuit levels. At the
system level, enhanced QoS and cell capacity are provided through the use
of a dual antenna receiver. Spatial diversity was observed to result in an
average improvement of 4-10 dB in the SNR.

The multi-million gate design is discussed in terms of hardware/software
partitioning with an emphasis on chip-level power management. Distributed
and centralized power management techniques are presented and measurements
are discussed in details.

Drilling down into the architecture, an example of circuit based
optimization is presented. A compact architecture and implementation for a
direct digital frequency synthesizer is discussed.

Finally, multi input multi output (MIMO) orthogonal frequency division
multiplexing (OFDM) is considered as an alternative to CDMA for wideband
wireless application that require high channel capacity. The system
architecture and experimental measurements are discussed.

Speaker's Biography:

Ahmed M. Eltawil received his doctorate degree from the University of
California, Los Angeles (UCLA) in 2003, prior to that he received his B.Sc
and M.S. from the Electronics and Communications Department, Cairo
University, Egypt in 1997 and 1999 respectively.  While at UCLA, his
research was focused on the development of algorithms and techniques to
architect low power VLSI ASIC designs for wireless broadband code division
multiple access (CDMA) based systems. From January 2001 till August 2003,
he was affiliated with Innovics Wireless, Los Angeles, California, where he
was appointed director of the VLSI engineering group. At Innovics, he
worked on the development of a diversity processing baseband modem for the
third generation WCDMA mobile terminal. Since September 2003, he is with
UCLA, where he is currently a research scientist at the electrical
engineering department investigating system architectures for multi-input
multi-output (MIMO) wireless communication systems. His research interests
include communication system design, system on a chip architecture, digital
integrated circuits and digital signal processing.