Improving the accuracy of Indoor localization System using smart phones

Abstract

Modern smartphones are a great platform for Location Based Services (LBS). While outdoor LBS for smartphones has proven to be very successful, indoor LBS for smartphones has not yet fully developed due to the lack of an accurate positioning technology. Smartphones that uses the innate ability of mobile phones to detect wifi signal strength using wifi analyzer. This strategy usesthe results of trilateration technique which determines the position of users in indoor areas based on Wi-Fi signal strengths from access points (AP) within the indoor vicinity. In this paper, percentage of signal strengths obtained from Wi-Fi analyzer in a smartphone were converted into distance between users and each AP. But due to inaccuracy of only trilateration technique, we used a method to improve the result i.e least square trilateration.The method of least squaresis a standard approach to the approximate solution of overdetermined systems. A user‟s indoor position could then be determined using a formula proposed based on this trilateration technique.