Geo-location using received signal statistics

A novel approach to geo-locate sensor-nodes in a Ricean fading environment is presented. For localization, this work considers autocorrelation characteristics of short term fading that are typically averaged out in traditional signal-strength based algorithms. Location attributes of the sensor nodes are determined by minimizing the squared error between the estimated autocorrelation function and its theoretical approximation. The theoretical approximation of the autocorrelation function is derived in closed form from Aulin's three-dimensional channel model. It is shown that despite noisy measurements and weak line-of-sight signal, the proposed method estimates coordinates of sensor nodes within an error of less than ±5% for signal-to-noise ratios higher than 20 dB.