Time-Frequency Spectrum Research Of New Binary Offset Carrier Modulation And Its Acquisition Algorithm Disign

With the development of times, navigation system become more and more widely used in scientific research, military confrontation, as well as daily life. Therefore, the accuracy, sensitivity requirements, safety performance and anti-jamming performance of distance, speed, positioning accuracy provided by navigation system will increase. The aim of this paper is improving the BOC modulation mathematical model to put forward the new offset carrier modulation:Frequency Chirp-BOC (FC-BOC) and Frequency Hop-BOC (FH-BOC). The new modulation is generated by replace the binary offset carrier of BOC with chip or hop offset carrier, in order to inherit the nature of BOC and also have several unique natures.Simulations and experiments show that FC-BOC modulation and FH-BOC modulation retain the primary advantages of BOC modulation; on the other hand, acquire a narrow and sharp correlation main-peak with extremely suppressed side-peaks for avoiding multiple correlation peak ambiguity naturally, flat power spectral density function similar to band-pass white noise for stealth properties and anti-interception performance; furthermore, as the FH-BOC modulation’s hopping is achieved in the baseband, FH-BOC modulation could overcome traditional hopping modulation’s useless of precise positioning of the carrier phase. In the case of the above excellent properties, the new offset carrier modulation’s (FC-BOC and FH-BOC) generation and receiver algorithm are similar to the structure of BOC modulation.This paper proposes FC-BOC modulation on the basis of original BOC modulation, compares the acquisition result on condition that wether the subcarrier has Doppler shift or not at receiving terminal, meanwhile simulating FC-BOC(31,1)’s results under different signal to noise ratio conditions by using match filter/FFT algorithm to verify the correctness and validity of the algorithm.Finally,summarizing the whole article and the suggestion on the further follow-up and improvement is presented.