摘要：The radionavigation satellite service (RNSS) portion of the RF spectrum is overcrowded, especially on L1 where GPS, Galileo, Compass overlap portions of one another’s signal frequencies and GLONASS signals occupy more than 11 MHz of nearby bandwidth. Indeed, even those bands that have not been used so far will certainly be shared by many systems in the near future. Therefore, the search of alternative frequency resources is something that must inevitably occur with a high probability in the coming years.
