| This thesis considers the interference resolution for adaptive arrays. Two types of Direct Radiating Array (DRA) architectures, namely, uniform linear arrays (ULA) and planar circular arrays (PCA), are considered. The purpose is to clarify the concept of interference cancellation capability. It is often stated in the literature that an {dollar}Nsb{lcub}E{rcub}{dollar}-element array has {dollar}Nsb{lcub}E{rcub}{dollar}-1 degrees of freedom which can be used to optimize one desired user and cancel out {dollar}Nsb{lcub}E{rcub}{dollar}-2 interferers. However, we find that this interference cancellation capability of an antenna array must be modified as a function of {dollar}Nsb{lcub}E{rcub}{dollar} and the array architecture.; We first considered the Uniform Linear Array (ULA) structure which is the simplest form of DRA. For each {dollar}Nsb{lcub}E{rcub}{dollar}, simulations are run to find the maximum number of users supportable while acceptable antenna performance, defined as having a signal-to-interference-plus-noise ratio (SINR) within 1 dB of the SINR achieved in a zero-interference environment, is achieved.; We then extended this study to a two-dimensional DRA, the planar circular array (PCA). The resolutions for signals coplanar and non-coplanar to the PCA are examined.; Finally, three modifications on the adaptive algorithms employing decision feedback are proposed and investigated. (Abstract shortened by UMI.)... |
