Research And Implementation Of Tracking Loop Algorithm For TC-OFDM Positioning Receriver

With the advent of smart phones and the rise of the mobile Internet,the concept of location services has gradually become popular.The accurate location information can bring great convenience.However single outdoor location services can no longer meet people's needs,providing accurate indoor positioning is imminent.Therefore,TC-OFDM positioning system has been developed to solve indoor location problems.The tracking loop is a core component of the TC-OFDM positioning receiver and its performance directly affects the accuracy of the positioning result.In the indoor environment,the tracking accuracy will be greatly affected because of the influence of thermal noise,dynamic stress and multipath signals,thus making the positioning results appear deviation.In this dissertation,the thermal noise,dynamic stress and multi-path problems in TC-OFDM indoor positioning system tracking loop based on terrestrial broadcast network are studied.By modeling the interference characteristics of thermal noise and dynamic stress,an improved tracking loop algorithm for positioning receiver is proposed.Based on the research of multipath signal generation and propagation characteristics,a new multipath suppression method is proposed.Then,the improved tracking loop algorithm is simulated on the MATLAB platform,and the related performance testing is completed on the baseband hardware platform of the positioning receiver based on FPGA +ARM.Experimental results show that the proposed improved algorithm can effectively improve the stability and accuracy of the tracking loop.The main research contents are as follows:(1)The relationship between carrier noise ratio,noise bandwidth and tracking error is analyzed,and the carrier-to-noise ratio estimation algorithm is further studied.An adaptive tracking loop design for TC-OFDM positioning system is proposed and the tracking loop Robustness.(2)The characteristics of multipath effect in indoor environment and the corresponding multipath error model and the limitations of traditional multipath suppression algorithm in TC-OFDM system are analyzed.Then a multi-path suppression algorithm based on linear regression is proposed,which reduces the multipath error of the loop.(3)Based on the above tracking loop simulation experiments.Then design the corresponding baseband hardware modules to build a real test environment for the above tracking loop performance testing.