Designed method for satellite navigation signal system with mixed modulation of direct spread spectrum and frequency hopping

A design method for a satellite navigation signal system with mixed modulation of direct spread spectrum and frequency hopping, wherein a navigation signal comprises multipath signal components and the method comprises:

• acquiring design requirements of multipath signal components, wherein the design requirements of the multipath signal components comprise:
• baseband code sequence generation design, signal separation and recombination design, frequency hopping modulation design and direct spread spectrum signal generation design;
• designing a baseband code sequence generation of the multipath signal components as follows:
• modulating a spread spectrum code sequence of the multipath signal components, followed by mixing and multiplexing with signal components corresponding to a same frequency point, and forming the baseband code sequence according to a power ratio of each path of signal components;
• separating the signal components corresponding to the baseband code sequence according to navigation signal receiving environment conditions to obtain multipath separated radio frequency signals;
• carrying out signal recombination modulation on the multipath separated radio frequency signals, wherein if separated radio frequency signals corresponding to a current communication path are authorized signals, a frequency hopping pattern is controlled through a frequency hopping code sequence, and a mixed frequency synthesis modulation is carried out according to a central frequency point of the frequency hopping pattern and a frequency of the authorized signals to obtain multipath modulated recombined signal components;
• if separated radio frequency signals corresponding to the current communication path are unauthorized signals, a direct combined radio frequency modulation is performed according to a preset signal frequency point and a frequency of the unauthorized signals to obtain multipath modulated recombined signal components;
• and amplifying a signal power of each path of modulated recombined signal components according to a center frequency point difference of the multipath modulated recombined signal components to obtain multipath direct spread spectrum navigation signals for transmission.