Novel Adaptive Array Algorithms and Their Impact on Cellular System Capacity

Abstract

This research focuses on the application of

adaptive arrays to the Advanced Mobile

Phone Service (AMPS) and Code Division

Multiple Access (CDMA) cellular systems.

Adaptive arrays have been proposed as

early as in the 1960s to improve the signal

quality, but most of its applications were

restricted to defense purposes. Recently,

there has been a surge in interest of

applying adaptive arrays for cellular

systems. This work introduces new blind

adaptive array algorithms for AMPS and

CDMA signals. The theoretical capacity

limit using an adaptive array at the base

station for an AMPS cellular system is

derived in this work. One of the significant

contributions in this research is a macrocell

channel model which provides

angle-of-arrival (AOA) statistics of the

multipath components. Practical issues

involved in the implementation of an

adaptive array are addressed and the

author's implementation of an 8-element

adaptive array operating at 2.05 GHz is

explained. This research also analyzes the

capacity that can be offered by an adaptive

array in a system where CDMA users

co-exist with existing AMPS users. A novel

cellular CDMA system which exploits

adaptive arrays is introduced and the

capacity offered by this system is

compared with existing and other systems

exploiting spatial dimension.