A B1I signal fast acquisition scheme of Beidou soft receiver

With the rapid development of the Beidou system, it is important to research the acquisition of B1I signal. In order to acquire the MEO/IGSO satellites signal modulated with 1 kbps NH code in interference environment effectively and quickly, a signal acquisition scheme which is the combination of an improved half bits differential acquisition method and 3-points conic fitting method to get fine frequency is proposed. The experiment results show that the improved half bits differential acquisition method, compared with the traditional acquisition method, acquired Beidou B1I signal more successfully, especially for the weak signals, And 3-points conic fitting method provided fine carrier frequency which is accurate enough for the signal tracking.