Improved Indoor Localization System Using Statistical AP Selection Method Based on RSSI

Nowadays, the demand for nursing care service has been increasing rapidly with the growth of aging population and presence of chronic diseases. To ease the problem of workforce shortage in healthcare facilities, a novel remote monitoring system is proposed based on wireless communication. The developed system applied collected Received signal strength indicator (RSSI) for acquiring the position of patients and the elderly. Several methods based on RSSI are usually used like maximum likelihood estimation and trilateration. However, accuracies of these methods are not ideal for localization due to abnormal RSSI value caused by random reflection or refraction of radio propagation. In this paper, statistical AP selection method is applied to achieve distribution situation of trilateration results. Then Centroid and Kernel Density Estimation method are utilized to obtain estimation points according to distribution of combination. The experimental result shows that the localization system is sufficient with the improved strategy on positioning.