signal transmission system RADIO via a geostationary communications satellite, including communications with mobile terminals

Linvention relates to a radio signal transmission system via a primary geostationary communication satellite (MS) and one or more auxiliary satellites (DSR1) "co-located" on the same orbit, space diversity. The distance between an auxiliary satellite (DSR1) of the main satellite (MS) is in a range of 200 to 400 km. The system includes conventional bidirectional transmission links (LM0 -ld0, lbi) between mobile earth terminals (MTU) and the main satellite (MS) and between it and a ground station (ST1). Furthermore links unidirectional transmission (lm1, ll0) are provided between the auxiliary satellites (DSR1) and the main satellite (MS). particularly applicable to a mobile communication service with mobile terminals via a geostationary satellite.