Impact of antenna array geometry on the capacity of mimo communication system

Abstract

More services and higher data rates are the demands of future wireless communication system end users. In order to accommodate these expectations while maintaining robustness against wireless impairments, contemporary technologies have to be developed. Multiple-input multiple-output (MIMO) techniques stand as a strong candidate to allow robustness against channel fading and interference as well as to enable high data rates.

This dissertation investigates the impact of different array geometries on the capacity of MIMO communication systems. Five different array configurations, Uniform Linear Array, Non-Uniform Linear Array, Uniform Circular Array, Hexagonal Array and Star Array, are being used to compare their performance from capacity point of view. The expression of the capacity of a MIMO communication system is derived from an information-theoretic approach and is altered to introduce the impact of array geometry on the system capacity. Using this expression the capacities of MIMO systems with different array geometries are compared. Also the impact of increasing the number of element of the array and changing the inter-element spacing of the array elements are examined. The significant increase in achievable capacity using array of antennas at both end of the transmission link is observed to justify the ascendancy of MIMO system.