Research On Pseudo-code Ranging Method Based On The CMMB

Wireless navigation and positioning are playing an increasingly important role in modern society, and they are used widely in many aspects, from the national defense security, rescue and relief to personal travel. The rising CMMB technology in recent years not only provides convenient way to receive mobile video, but also drives up the research on applying CMMB to ranging and positioning. This paper is based on the research project of CMMB positioning receiver.It combines the pseudo-code ranging and the CMMB for positioning, and builds the experimental platform, to lay the foundation of the CMMB-positioning.Firstly the paper starts with the study of the existing ranging and positioning theory, and the CMMB system is analyzed, including its network structure, OFDM modulation technique,and the pseudo-code in broadcasting signal. The result shows that the present CMMB system can not meet the requirements of the the function of pseudo-code ranging and positioning.Based on the result, the original CMMB system is modified and the ranging signal is added.The paper designs the positioning network, positioning message and the ranging code. The OFDM-modulated ZC sequence is chosen as the ranging code. Then based on the modification,the launching platform is built, and the output are tested and analyzed. At last the acquisition of the ranging code generated by the experimental platform is analyzed. The matched filter method is used and the effect of the white Gaussian noise is simulated.The simulation of the ranging code shows that the proposed ranging code has good correlation and cross correlation properties, available for pseudo-code ranging in CMMB.The outputs of the launching platform are consistent with the theoretical analysis, validating the correctness of modification. The simulation of the successful acquisition of the ranging code indicates that the pseudo-code ranging based on the CMMB is feasible.