Wi-Fi Received Signal Strength-based Indoor Localization System Using K-Nearest Neighbors fingerprint integrated D* algorithm

The indoor localization system is essential since the Global Positioning System cannot give an accurate position indoors, especially when several floor plans are considered. WiFi received signal strength becomes an alternative indicator for indoor localization systems. The experiment proposed a localization system created by integrating and working between the K-Nearest Neighbors algorithm and the D*algorithm. The result illustrates the optimal path from the start point to the target point by avoiding the obstacle performing exceptionally well. The K-Nearest Neighbors algorithm provide the result for localization with Root Mean Square Errors of displacement at 1.190 meters, 2.491 meters, and 1.363 meters of X-Axis Y-Axis, respectively. The proposed indoor localization system can have various applications considering different environmental factors in different applications, such as the size of unmanned aerial vehicles when applying indoor unmanned aerial vehicles.

I. Introduction

Wi-Fi received signal strength (RSSI) can help to find a relationship between two positions to translate into distance values in indoor localization. Wi-Fi RSSI measures in decibel-milliwatts(dBm). The Wi-Fi RSSI values have typical negative values ranging between 0dBm (excellent signal) and -110dBm (low signal). Signal strength is taken to calculate the distance between nodes from the signal attenuation values. The Wi-Fi RSSI values are not complex to understand. If the RSSI value is high, it means the received signal is strong or high-quality, that is, the transceivers are close to each other, but if the Wi-Fi RSSI values are small, this indicates that the received signal is low or the system with the receiver and transmitter is far apart, depending on obstacles and the environment in which the signal has interfered. Examples of obstacles that can interfere with the Wi-Fi RSSI include walls, ceilings, objects, multiple routes, etc.