Dimitris Kalofonos

Advanced Physical Layer Techniques for CDMA Broadband Wireless Integrated Services Networks

Thursday, May 17, 2001

ABSTRACT

There is currently an intense interest in conducting research, which would make possible the efficient deployment of future Broadband Wireless Integrated Services Networks (B-WISN). B-WISN can be considered in general as a wireless extension of wire-line Broadband Integrated Services Networks (e.g. B-ISDN, ATM). CDMA-based systems have gained wide acceptance among the candidate technologies, because they combine resistance against interference and multi-path fading, as well as flexibility and scalability since no frequency planning is necessary.

In this dissertation we first introduce the concept of B-WISN by presenting the basic characteristics and supported services. We examine the performance of advanced physical layer techniques capable of supporting the requirements of B-WISN applications. Flexible CDMA-based schemes, namely Multi-Carrier CDMA (MC-CDMA), Multi-Code CDMA (MCD-CDMA), and Variable Spreading Gain CDMA (VSG-CDMA), are proposed for application in B-WISN. We present our results on Adaptive Detection of MC-CDMA in fast fading wireless channels, on the performance of Concatenated Interleaved Coding and Iterative Decoding schemes applied to both DS-CDMA and MCD-CDMA systems, and on the performance of coded high data-rate VSG-CDMA systems with random sequences and low spreading gains. With respect to directions for future research, we demonstrate the need to leverage our results on the performance of physical layer techniques in order to optimize higher-layer network functions in B-WISN.

Thesis Committee:
Prof. John G. Proakis (N.U., Academic advisor)
Prof. Masoud Salehi (N.U.)
Prof. Arthur Giordano (N.U., Verizon Laboratories)
Prof. Milica Stojanovic (M.I.T.)