Uniform Circular Antenna Array Applications in Coded DS-CDMA Mobile Communication Systems
Abstract
Presently, the uniform linear array (ULA) is the most commonly used antenna system for a sectorized cell system like commercial cellular systems. However, in many omni-directional cell communication systems, such as ground-based military communications, interest in using the uniform circular array (UCA) has greatly increased. This thesis examines the use of an equally spaced circular adaptive antenna array at the mobile station for a typical coded direct sequence code division multiple access (DS-CDMA) communication system. The author analyzed the performance of a randomly orientated adaptive UCA in the forward channel (base station to mobile station) of a coded multi-cell DS-CDMA system. Using a 3- and 4-element UCA, the capacity and performance of different cellular systems under a range of shadowing conditions, with and without antenna sectoring at the base station and for various user capacities, were simulated using the Monte Carlo method. The results for both ULA and UCA are compared and presented in this thesis. The simulation results show that, generally, the performance of the system with the adaptive UCA is better than, or at least on par with, the system with the adaptive ULA. In addition, the 4-element adaptive array can "null out" up to three interfering signals, thereby increasing the system's capacity. Furthermore, sectoring techniques significantly reduced the amount of inter-cell interference and improved the system's performance, thereby increasing the number of mobile stations allowed within the cell. The capacity of the system with the 3- and 4- element adaptive UCA was increased by 5.8 times (with 60 degree sectoring) and 2.8 times (with 120 degree sectoring), respectively. (37 figures, 9 refs.)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2003
- Accession Number
- ADA415205
Entities
People
- Tian B. Seow
Organizations
- Naval Postgraduate School