Power Delay Profile (PDP) offers valuable insights into the propagation power fading of Line of Sight (LoS) and Non Line of Sight (NLoS) paths, making it a potential resource for ranging estimation. Despite its potential, the research on the lower bound of ranging error for PDP-based ranging is limited. This paper addresses this gap by introducing the Cramér–Rao bound (CRB) for Power Delay Profile (PDP) based ranging and Received Signal Strength Indicator (RSSI) based ranging, considering a specific indoor channel fading model. Through extensive simulations and analysis, we demonstrate the superiority of PDP-based ranging over RSSI-based ranging. Our findings contribute to a deeper understanding of the potential benefits of PDP-based ranging techniques.