Research And Implementation Of TC-OFDM Positioning Baseband Signal Processing And Anti-multipath

With the concept of the Internet of things,the wisdom of the city proposed,Location Based Service has been widely integrated into people's daily lives.In terms of business,military and public safety,accurate positioning services of indoor and outdoor has an extremely important significance.However,relative to the outdoor environment,the indoor environment is very complex and changeable.The signal will be affected by obstructions as walls,ceilings and indoor objects.The obstruction will block the propagation of the signal and cause reflection,refraction and diffraction of the signal.The signal will eventually arrive at different times through multipath which seriously affected the accuracy.The thesis discuss the multipath effect in TC-OFDM indoor location system based on the terrestrial broadcast network,and also study the anti-achieve.The multipath effect is study from the channel modeling,and the multipath signal generation and propagation characteristics are analyzed.The anti-multipath design and improvement of the receiver is proposed,it can effectively reduce the impact of short multipath signals by 30%.Then,the improved anti-multipath algorithm is implemented on the MATLAB platform.Finally,the baseband hardware platform of positioning receiver is based on ARM+FPGA.The main research contents include:(1)This thesis introduces the architecture of TC-OFDM positioning systems and the design of the signal system.Then,analyze the mutual influence and correlation between superposition code and OFDM signal.Introduce TC-OFDM positioning principle and main interference factors in indoor location.(2)The causes and characteristics of multipath signals are analyzed,and the channel model in the traditional multipath environment is introduced.A multipath channel model for indoor complex environment is proposed.(3)This thesis introduces the TC-OFDM baseband signal processing flow.Then the effect of multipath effect on the acquisition and tracking model is analyzed.An anti-multipath acquisition algorithm based on cyclic decision is proposed.Then,the anti-multipath design Code-tracking loop is put forward in the complex indoor environment,and proposes the NC-EML5 algorithm.(4)Based on the anti-multipath design and simulation experiment mentioned above,this thesis completed the design and implementation of the baseband hardware module.Finally,the performance of the anti-multipath designs studied in this paper is tested.