Inspired by the overlap communication theory, a new onshore radio positioning system which superimposed on terrestrial digital transmission system is proposed in this paper. This system overlaps but not affects existing terrestrial digital broadcasting.At the receiver, a reconstruction/cancellation algorithm.is implied to capture the navigation signal and positioning measurements precisely.This paper focus on the construction of overlap system,spreading navigation signal and the capture of positioning measurements.We give a method to generate spreading navigation signal and overlap with terrestrial digital transmission system.The method can reduce the performance degradation due to pilot interference. We also proposes a reconstruction/cancellation algorithm which can solution the capture performance deterioration caused by overlapped system . The simulation results show that this system proposed in this paper can be used in terrestrial digital transmission system and provide good positional function.
