Design And Realization Of GNSS-merging Indoor And Outdoor Positioning Receiver Baseband

In recent years,as the strategic emerging industry,LBS(Location Based Service)has started to become a part of people's life.Although outdoor positioning based on GNSS(Global Navigation Satellite System)has been widely applied,it is unable to provide indoor positioning service limited to signal-sheltered.With the progress of society,the development of economic and the rapid growth of large buildings,the demand for high-precision indoor positioning is also growing in the fields of daily life,emergency rescue and public security.At the same time,indoor positioning merges with GNSS to realize indoor and outdoor seamless positioning has also become the development tendency of LBS.This paper focuses on TC-OFDM(Time&Code Division-Orthogonal Frequency Division Multiplexing)signal model to design receiver baseband based on TC-OFDM signal model.At the same time,GNSS baseband platform is merged with TC-OFDM baseband to design and realize GNSS-Merging indoor and outdoor positioning receiver Baseband.The detailed research contents and achievements are as follows:(1)According to TC-OFDM signal model,signal acquisition algorithm of TC-OFDM receiver baseband is researched.It includes the selection of PN sequence acquisition methods,weak signal acquisition algorithm based on strong signal's TPI(Timing Prior Information)and optimization of Gold code access.(2)GNSS-Merging indoor and outdoor positioning receiver baseband interface is deeply researched.It includes the selection of mergence scheme,a data communication method based on mailbox delivery and clock switch system.(3)A GNSS-Merging indoor and outdoor positioning receiver baseband general scheme is introduced,and all functions are realized in FPGA+CPU structure.