Transmitter Location-Independent Path Loss Exponent Estimation via RSS Measurements With Shadowing Effect

Path loss exponent (PLE) is one of the key parameters that characterizes the channel attenuation properties. Existing estimation strategies for PLE mostly consider scenarios of free-space transmission and rely on information exchange between transmitters and receivers. These approaches have limitations such as high costs, low security, and insufficient consideration of complex environments. This letter, based on the geometric path loss distribution model in wireless random networks established in [1], implements a joint analysis and estimation of PLE and shadowing variance, taking into account shadowing effects and without transmitter's location. First, the objective function is formulated using maximum likelihood estimation. Due to the complexity of the objective function's mixed second-order characteristics, the first-order and second-order properties of the objective function with respect to each variable are analyzed sequentially. Finally, through extensive simulation experiments and comparisons with Cramer–Rao lower bound ´ (CRLB), the consistency and effectiveness of the theoretical analysis and experimental results are verified.