Fault Tolerant Dynamic Antenna Array in Smart Antenna System Using Evolved Virtual Reconfigurable Circuit

Abstract

A majority of applications require cooperation of two or more independently designed, separately located, but mutually affecting subsystems. In addition to good behavior of each of the subsystems, an effective coordination is very important to achieve the desired overall performance. However, such a co-ordination is very difficult to attain mainly due to the lack of precise system models and/or dynamic parameters. In such situations, the evolvable hardware (EHW) techniques, which can achieve the sophisticated level of information processing the brain is capable of, can excel. In this paper, a new virtual reconfigurable circuit based drive circuit for array elements in smart antenna using the techniques of evolved operators is presented. The idea of this work is to develop a system that is tolerant to array element failure (fault tolerance) by utilizing phased array input programmer connected to a programmable VLSI chip. The approach chosen here is based on functional level evolution whose architecture contains many nonlinear functions and uses an evolutionary algorithm to evolve the best configuration. The system is tested for its effectiveness by choosing a real-time phase control in three element array of smart antenna with three input phases and introducing different element failures such as: element fails as open circuit, sensor fails as short circuit, noise added to individual element, multiple element failure etc.. In each case the mean square error is computed and used as the performance index.