In modern LEO satellite communication systems, numerous singnals have to be located in a same frequency band because of limited spectrum resources. Thus, a bandwidth-efficient modulation, which has constant envelope characteristics and can alleviate signal distortions when using saturated power amplifiers is necessary to combine several signals to share the frequency resource. This paper presents the analytic interplex modulation expression in LEO satellite spread spectrum communication systems, and obtains the relationship of modulation efficiency, error rate and power ratio. Lastly, the appropriate choice of power radio is obtained in the case of three signals or four signals multiplexing. The work of this paper is an important guideline for constant envelope combined methodologies in LEO satellite spread spectrum communication systems.
Fine time uplink synchronization for frequency-hopped spread spectrum satellite communication systems.
