Unknown Transmit Power Energy-Based Source Localization in Wireless Sensor Networks

Passive source localization is an important area of research. In this paper, a received signal strength difference (RSSD) based localization technique is presented for wireless sensor networks. The advantage of this solution is that the transmit power does not have to be known. It is an effective low complexity technique as it eliminates the transmit power estimation required with other approaches. The uncertainties due to the signal propagation parameters are eliminated by using the received signal strength differences from known sensors. This yields a set of equations using signals from the source to sensors with known positions assuming a log-normal path loss model. The constrained weighted least squares (CLS) technique is used for location estimation using these equations. Results are presented which show that the performance of the proposed method achieves the Cramer-Rao lower bound (CRLB) for a sufficiently high signal to noise ratio (SNR).