Best linear unbiased estimator algorithm for received signal strength based localization

Locating an unknown-position source using measurements from an array of spatially separated sensors with low complexity is quite necessary in many applications. In this paper, a linear least squares (LLS) method, which is a best linear unbiased estimator, is proposed to estimate the unknown-position source location based on the received signal strength (RSS) measurements. It is proved that the performance of our proposed method is identical to that of an existing LLS technique but the former is more computationally efficient. A relaxation method is also introduced to extend the LLS methods for RSS-based positioning with unknown path-loss factor. Furthermore, numerical examples are included to evaluate the performance of proposed algorithm by comparing with the existing LLS approach and their theoretical position variances as well as Cramér-Rao lower bound.