A Novel TOA-Based Source Localization Algorithm in Wireless Sensor Networks

With great development of wireless sensor networks (WSNs) technology, one of its important applications, source localization, has attracted numerous interests of recent scientific researches. Among different kinds of methods, techniques based on time difference of arrival (TDOA) and time of arrival (TOA) are practical and of high accuracy. In consideration of TDOA-based methods' inherent noise correlation and loss in signal-to-noise ratio (SNR), this paper focuses on TOA-based source localization method in WSNs. We formulate the localization problem as a maximum-likelihood (ML) problem, and exploit the relationship between the emitting time constant of signal and the coordinate of source to remove the time constant in the ML function. Then the conjugate gradient method is utilized to obtain the final solution. Simulation results validate the convergence of the proposed algorithm and demonstrate its better performance than some existing TDOA based techniques.