REDUCED IN SIDE LOBE LEVEL (SLL) USING GENETIC ALGORITHM OF SMART ANTENNA SYSTEM

Abstract

The demand for wireless communications constantly grows the need arises for better coverage, improved capacity, and higher transmission quality. Thus, a more efficient use of the radio spectrum is required. Smart antenna systems are capable of efficiently utilizing the radio spectrum and promise an effective solution to the present wireless system problems while achieving reliable and robust high speed high-data-rate transmission. Smart antennas dynamically adapt to changing traffic requirements whose adaptive beam forming approach can be studied with the help of different adaptive algorithms. The fundamental idea behind smart antennas is to improve the performance of the wireless communication system by increasing the gain in a chosen direction. This can be achieved by pointing the main lobes of the antenna-beam patterns towards the desired users. Smart antenna system combines multiple antenna elements with a signal processing capability to automatically optimize its radiation and/or reception pattern in response to the signal environment. In this paper proposed a very simple and powerful method for the synthesis of linear array antenna. This method reduced the desired level of side lobe level (SLL) as well as to steer the main beam at different-different angle. A new method for adaptive beam forming for a linear antenna arrays using genetic algorithm (GA) are also proposed. Genetic Algorithm is an iterative stochastic optimizer that works on the concept of survival of the population values based on the fitness value. An adaptive genetic algorithm has been used in linear array to optimize the excitation levels of the elements resulting in a radiation pattern with minimum side lobe level. These algorithm can determinate the various values of side lobe level and phase excitation for each antenna to steer the main beam in specific direction.