Indoor Positioning System: A Brief Review of Its Technologies and Signal-Filtering Techniques

In recent years, the growing demand for location-based services has made positioning systems indispensable for mobile device users. Although the Global Positioning System (GPS) is widely used for outdoor positioning, its efficacy is significantly reduced due to obstructions that block or weaken the signal. To address this issue, Indoor Positioning Systems (IPS) offer a viable solution for indoor environments. This paper presents a comprehensive literature review of IPS from sources such as Science Direct and IEEE Xplore using the PRISMA flow diagram for systematic review. We explore the latest techniques in IPS, discuss its challenges, and examine its application in various domains to provide an updated overview of the current trends and challenges in the field. We highlight that trilateration and Kalman filtering are the predominant methods for location determination and filtering.