Comparative Studies on BOC Signal Performance in Multipath Environment

It is well known that in indoor environment performance of GNSS-based positioning are strongly limited by several factors. Acquisition of weak signals is critical, visibility of a sufficient number of satellite is not granted, and the SIS received at the antenna propagates via multiple paths. Indoor signal acquisition can be aided by external elements providing augmentation signals through dedicated links or by means of communication channels (e.g. Assisted GPS) but the fine pseudorange estimation cannot be improved by external aids. Even differential corrections are not effective since a user few meters far away by a reference station can experience very different multipath conditions. The navigation receiver must embed multipath rejection strategies in order to improve the signal tracking and identify and minimize or correct the multipath effects on the final position estimation.