A Modification Strategy of Maximum Likelihood Method for Location Estimation Based on Received Signal Strength in Sensor Networks

This paper investigates a scheme to improve a location estimation method for higher estimation accuracy in sensor networks. For the location estimation method, we focus on the maximum likelihood method based on the measurements of received signal strength and its known probability distribution. Using some statistical properties of the estimate obtained by the maximum likelihood method in a simplified situation, we propose a modification of likelihood function in order to improve the estimation accuracy for arbitrary situation. However, since the proposed scheme is derived under a special assumption for the simplification, we should examine the impact of the proposed scheme in more general situations by numerical simulation. From the simulation results, we show the effectiveness of the proposed modification especially in the cases of small number of samples (namely, the measurements of received signal strength) and the channel model with exponential distribution.