Patent EA-000972-B1 (EA)
Title: A mobile-link system for a radio communication system with diversity reception of selected uplink signals for transmitting downlink signals
Inventor: HASSAN AMER AREF
IPC: H04B7/185
Filed: 1996-12-05
Abstract: 1. A mobile-link system for a radio communication system with diversity reception of selected signals for transmitting uplink signals comprising: a) a first mobile-link assembly (16) for receiving mobile uplink signals including zone-one uplink signals transmitted from mobile stations (26) located in a first zone (24a) of a coverage area (24) and zone-two uplink signals transmitted from mobile stations (28) located in a second zone of said coverage area (24), and for outputting received zone-one uplink signals and received zone-two uplink signals; b) a second mobile-link assembly (18) for receiving mobile uplink signals transmitted from mobile stations (26,28) in said coverage area (24) and outputting received zone-two uplink signals and not zone-one uplink signals, and said second mobile-link assembly (18) for transmitting mobile downlink signals to at least said first  c) a satelliite feeder-link assembly(20) for conveying said received zone-one signals outputted from said first (16) and second (18) mobile-link assemblies to an earth station (14); d) a combiner (52) located in an earth station (14) for diversity combining said received zone-two uplink signals received by both said first (16) and second (18) mobile-link assemblies so as to produce diversity resultant signals corresponding to zone-two uplink signals received at said first (16) and second (18) mobile-link assemblies. 2. The mobile-link system of claim 1, wherein said second mobile second mobile-link assembly (18) includes: a) a transmit-receive antenna (36) including transmit-receive feeds (56) for transmitting mobile downlink signals and receiving mobile uplink signals, and transmit feeds (58) for transmitting mobile downlink signals; b) a secondary receiver (40) for processing mobile uplink signals received by said transmit-receive feeds (56); c) a mobile-link transmitter (42) for outputting mobile downlink signals to said transmit-received feeds (56) and transmit feeds (58) of said transmit-received antenna (36) for transmission of mobile downlink signals to mobile stations (2, 28) in said first zone (24a) and said second zone (24b); d) a duplexer assembly (38) coupled to said secondary receiver (40), mobile-link transmitter (42), and transmit-receiver antenna (35) for directing received uplink signals from said transmit-receive feeds (56) to said secondary receiver (40) and for directing mobile downlink signals from said mobile-link transmitter (42) to said transmit-receive feeds (56). 3. The mobile-link system (10) of claim 2, wherein the first mobile-link assembly (16) includes: a) a receive antenna (30) for receiving zone-one and zone-two uplink signals; b) a primary receiver (32) for processing zone-one and zone-two uplink signals received by said receiver antenna (30). 4. The mobile-link assembly of claim 3, wherein the first (16) and second (18) mobile-link assemblies are located in a satellite (12) and coupled to a satellite feeder-link assembly (20), said satellite feeder-link assembly (20) for conveying said received mobile uplink signals outputted from said first and said second mobile-link assemblies (16, 18) to an earth station (14). 5. The mobile-link system (10) of claim 4, wherein said satellite feeder-link assembly (20) convey said receiver uplink signals to said earth station (14) by transmitting feeder-link downlink signals to said earth station (14). 6. The mobile-link system (10) of claim 5, wherein said a combiner (52) is located in said earth station (14) and combines said feeder-link downlink signals received at said earth station so as to produce said diversity resultant signals corresponding to zone-two uplink signals received at said first (16) and second mobile-link assemblies (18). 7. The mobile-link system (10) of claim 1, wherein said transmit-received antenna (36) of said second mobile-link assembly (18) is a reflector antenna (57) (57), and wherein said second mobile-link assembly (18) receives stations (26) in said first transmitted from mobile stations (26) in said first zone (24a) and does not received zone-one uplink signals transmitted from mobile stations in said second zone (24b). 8. The mobile-link system (10) of claim 2, wherein said transmit-received antenna (36) of said second mobile-link assembly (18) is a reflector antenna (57), and wherein said second mobile-link assembly (18) receives zone-two uplink signals transmitted from mobile stations (25) in said first zone (24a) and does not receive zone-one uplink signals transmitted from mobile stations (28) in said second zone (24b). 9. The mobile-link system (10) of claim 8, wherein said transmit-receive feeds (56) of said transmit-receive antenna (36) receives zone-two uplink signals transmitted from mobile stations (26) in said first zone (24a) and does not receive zone-one uplink signals transmitted from mobile stations (28) in said second zone (24b). 10. The mobile-link system (10) of claim 8, wherein said mobile-link transmitter (42) transmits zone-one downlink signals to said transmit feeds (58) of said transmit-receive antenna (36) and zone-two downlink signals to said transmit-receive feeds (56) of said transmit-receive antenna (36). 11. The mobile-link system (10) of claim 10, wherein said duplexer assembly (38) direct zone-two uplink signals from said transmit-receive feeds (56) of said transmit-receive antenna (36) to said secondary receiver (40) and for directing zone-two downlink signals to said transmit-receive feeds (56) of said transmit-receive antenna (36). 12. The mobile-link system (10) of claim 1, wherein said transmit-receive antenna (36) of said second mobile-link assembly (18) is a direct array antenna, wherein said transmit-receive antenna (36) receives the zone-one and zone-two uplink signals and wherein said second mobile-link assembly (18) processes said received uplink signals so as to output received zone-two uplink signals. 13. The mobile-link system (10) of claim 2, wherein said transmit-receive antenna (36) of said second mobile-link assembly (18) is a direct array antenna, wherein said transmit-receive antenna (36) receives the zone-one and zone-two uplink signals, and wherein said second mobile-link assembly (18) processes said received uplink signals so as to output received zone-two uplink signals. 14. The mobile-link system (10) of claim 13, wherein said second receiver (40) includes a receive beam former (64) for multiplying received uplink signals from said transmit-receive feeds (56) with predetermined beam forming weights so as to output zone-two uplink signals from said second mobile-link assembly (10). 15. The mobile-link system (10) of claim 14, wherein said mobile-link transmitter (42) include a transmit beam former (70) for forming downlink signals to be transmitted through said transmit-receive feed array (56) and transmit feed array (58) and transmit-receive antenna (36). 16. The mobile-link system (10) of claim 1, wherein said first zone (24a) is a central zone (24a) of said coverage area (24) wherein a mobile station (26) is located  in said central zone and said second zone (24b) is an edge zone (24b) bordering said central zone (24a) and a mobile station (28) is located in said edge zone. 17. A method for linking mobile-link system (10) for a radio communication system with mobile stations (26, 28), comprising: a) receiving at a first mobile-link assembly (16) mobile uplink signals including zone-one uplink signals transmitted from mobile stations (26) located in a first zone (24a) of a coverage area (24) and zone-two uplink signals transmitted from mobile stations (28) located in a second zone (24b) of said coverage area (24), and ouputting received zone-one uplink signals and received zone-two uplink signals; b) receiving at a second mobile-link assembly (18) mobile uplink signals transmitted from mobile stations (26, 28) in said coverage area (24) and outputting received zone-two uplink signals and not zone-one uplink signals, and transmitting from said second mobile-link assembly (18) mobile downlink signals to at least said first (24a)and second zone (24b) s of said coverage area (24); c) diversity reception in earth station combining a satellite feeder-link assembly said received zone-two uplink signals received by both said first (16) and second (18) mobile-link assemblies so as to produce resultant signals corresponding to zone-two uplink signals received at said first (16) and second (18) mobile-link assemblies. 18. The method of claim 17, wherein the first (16) and second (18)mobile-link assemblies are located in a satellite (12) and coupled to a satellite feeder-link assembly (20), and further including the step of conveying received mobile uplink signals outputted from said mobile-link assemblies (16, 18) to an earth station (14). 19. The method of claim 17, wherein said step of conveying received mobile uplink signals to an earth station (14) includes transmitting feeder-link downlink signals from said satellite feeder-link assembly (20) to said earth station (14). 20. The method of claim 17, wherein said diversity combining step includes combining feeder-link downlink signals at said earth station (14) so as to produce said diversity resultant signals corresponding to zone-two uplink signals received at said first and second mobile-link assemblies (16, 18). 21. The method of claim 17, wherein said step of receiving mobile uplink signals at said second mobile-link assembly (18) includes receiving with a reflector antenna (57) zone-two uplink signals transmitted from mobile stations (26) in said first zone (24a) and not receiving zone-one uplink signals transmitted from mobile stations (26) in said second zone (24b). 22. The method of claim 17, wherein said step of receiving mobile uplink signals at said second mobile-link assembly (18) includes receiving with a reflector antenna (57) zone-one and zone-two uplink signals transmitted from mobile stations (26) in said first zone (24a) an