Abstract
In this paper we present the localization using received signal powers for sensor networks. The purpose of this study is to develop the indoor positioning systems utilized IEEE std 802.15.4 based wireless sensor networks.The distance between nodes can be presumed by using the RSSI (received signal strength indicator) to use the wireless for the data communication in the sensor network. Therefore, it becomes possible for the position of the sensor node to presume by using the RSSI from a certain sending source if a number of base stations already measured the position.The variation of the RSSI is large because of the influence by the measurement environment. Therefore, it is necessary to acquire a lot of the RSSI data to improve the position estimation because a lot of error margins are included in the presumption distance. In this paper, we discuss a distance transformation model applying Friis equation or experimental results model. Namely, the signal powers distribution are modeled as the Rayleigh distribution. We propose an optimal distance model from the probability density functions of the signal powers.First, we describe its implementation on a ubiquitous device. Next, we examine the estimation of distance I with measurement values, and a method for estimating locations. Based on the above method we show the experimental results. Finally we mention a brief summary and future work.
