Telecommunications satellite channelizer

• US 6,628,920 B1
• Filed: 10/11/2000
• Issued: 09/30/2003
• Est. Priority Date: 07/25/1997
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Faris, Alan E., Wolcott, James L.
• Primary Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/686,584
• Time in Patent Office: 1,084 Days
• Field of Search: 455/427, 455/429, 455/430, 455/431, 455/12.1, 455/13.2, 455/13.3, 455/428, 455/423, 455/436, 455/438, 455/439, 455/445, 370/316, 370/318, 370/319, 370/325, 370/360, 370/331, 370/332, 342/352, 342/353
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04B 7/2045 SS-FDMA, FDMA satellite switching

Abstract

A telecommunications satellite channeliser (170) is provided for mapping RF signals between feeder links (160-162) and mobile link beams (210-212) based on a predefined frequency plan (FIGS. 7 and 8). The mobile link beams (240) define a coverage area (242) of a satellite (10). Each feeder link and mobile link beam comprises a plurality of feeder subbands and mobile subbands grouped to form feeder link channels (216-238) and mobile link channels (244-255). The channeliser (170) includes at least one feeder lead carrying a feeder link signal (160-162) associated with a ground station (14 and 16). A feeder link distribution network (175) is connected to the feeder leads and maps RF signals in the feeder links (160-162) onto a plurality of distribution leads as divided feeder signals. Channel multiplexers (182-184) are connected to the distribution leads. Each channel multiplexer (182) includes a set of band pass filters (190-201), each of which passes RF signals in a subset of feeder subbands corresponding to a single feeder channel in order to map a mobile link channel (244) and a feeder link channel (216) onto one another based on a predefined frequency plan. The channeliser (170) groups or multiplexes signals from a plurality of feeders into each beam. Fixed local oscillator up converters shift each composite mobile channel to a common band allocated to all beams. The frequency plan is defined such that beam handovers and ground station handovers may be performed without a need for at least one of switching, retuning and resynchronization of the telecommunications satellite and the mobile terminal.

Claims

1. A telecommunications satellite for mapping RF signals between feeder links and mobile link beams based on multiple predefined frequency plans, the mobile link beams defining a coverage area of the satellite, each feeder link communicating with a ground station, each feeder link containing feeder link channels, each mobile link beam containing mobile link channels, said satellite comprising:

a satellite transceiver receiving and transmitting RF signals in a first frequency range to and from ground stations via feeder links, said transceiver transmitting and receiving RF signals in a second frequency range to and from mobile terminals via mobile link beams; and

a processing subsystem mapping mobile link channels and feeder link channels onto one another based on at least two predefined frequency plans implemented by said telecommunications satellite that enable ground stations to perform ground station handovers without a need for at least one of switching, retuning, and resynchronizing the telecommunications satellite.

2. A telecommunications satellite according to claim 1, wherein said at least two predefined frequency plans include fewer frequency plans than the number of mobile link beams.

3. A telecommunications satellite according to claim 1, wherein a number of feeder link channels in one feeder link equals the number of mobile link beams.

4. A telecommunications satellite according to claim 1, wherein a mobile link beam includes at least two mobile link channels mapped from at least two associated feeder link channels in one feeder link.

5. A telecommunications satellite according to claim 1, wherein said processing subsystem assigns different frequency plans to adjacent mobile link beams and assigns a common frequency plan to mobile links remotely located from one another.

6. A telecommunications satellite according to claim 1, wherein said processing subsystem maps at least two mobile link channels in a single mobile link beam to a single feeder link.

7. A telecommunications satellite according to claim 1, wherein said processing subsystem maps at least two mobile channels from a first mobile link beam to a first feeder link according to a first frequency plan, and maps at least two mobile channels from a second mobile link beam to a second feeder link according to a second frequency plan.

8. A method of mapping RF signals, in a telecommunications satellite channelizer, between ground stations and mobile terminals, said method comprising the steps of:

transmitting and receiving RF signals in feeder links to and from ground stations, each feeder link being divided into feeder channels;

transmitting and receiving RF signals in mobile link beams to and from mobile terminals, each mobile link beam being divided into mobile channels; and

defining at least first and second frequency plans correlating feeder channels and mobile channels to one another, said first frequency plan mapping at least two mobile channels to a first feeder link and mapping no more than one mobile channel to a second feeder link, said second frequency plan mapping at least two mobile channels to said second feeder link and mapping no more than one mobile channel to said first feeder link.

9. A method according to claim 8, further comprising the step of setting the number of feeder channels in one feeder link equal to the number of mobile link beams.

10. A method according to claim 8, further comprising the step of setting the number of frequency plans equal to the number of feeder links.

11. A method according to claim 8, further comprising the step of mapping multiple mobile link channels in one mobile link beam onto feeder link channels from a single feeder link.

12. A method according to claim 8, further comprising the step of assigning a first frequency range to said feeder links and a second frequency range to said mobile link beams, said first and second frequency ranges differing from one another.

13. A method according to claim 8, wherein said defining step includes the step of defining a number of frequency plans equal to a number of feeder links, said number of frequency plans being less than the number of mobile link beams.

14. A telecommunications satellite for mapping RF signals between feeder links and mobile link beams based on multiple predefined frequency plans, the mobile link beams defining a coverage area of the satellite, each feeder link communicating with a ground station, each feeder link containing feeder link channels, each mobile link beam containing mobile link channels, said satellite comprising:

a satellite transceiver receiving and transmitting RF signals in a first frequency range to and from ground stations via feeder links, said transceiver transmitting and receiving RF signals in a second frequency range to and from mobile terminals via mobile link beams; and

a processing subsystem mapping mobile link channels and feeder link channels onto one another based on at least two predefined frequency plans implemented by said telecommunications satellite that enable ground stations to perform ground station handovers without a need for switching the telecommunications satellite.

15. A telecommunications satellite for mapping RF signals between feeder links and mobile link beams based on multiple predefined frequency plans, the mobile link beams defining a coverage area of the satellite, each feeder link communicating with a ground station, each feeder link containing feeder link channels, each mobile link beam containing mobile link channels, said satellite comprising:

a satellite transceiver receiving and transmitting RF signals in a first frequency range to and from ground stations via feeder links, said transceiver transmitting and receiving RF signals in a second frequency range to and from mobile terminals via mobile link beams; and

a processing subsystem mapping mobile link channels and feeder link channels onto one another based on at least two defined frequency plans implemented by said telecommunications satellite that enable ground stations to perform ground station handovers without a need for retuning the telecommunications satellite.

16. A telecommunications satellite for mapping RF signals between feeder links and mobile link beams based on multiple predefined frequency plans, the mobile link beams defining a coverage area of the satellite, each feeder link communicating with a ground station, each feeder link containing feeder link channels, each mobile link beam containing mobile link channels, said satellite comprising:

a satellite transceiver receiving and transmitting RF signals in a first frequency range to and from ground stations via feeder links, said transceiver transmitting and receiving RF signals in a second frequency range to and from mobile terminals via mobile link beams; and

a processing subsystem mapping mobile link channels and feeder link channels onto one another based on at least two predefined frequency plans implemented by said telecommunications satellite that enable ground stations to perform ground station handovers without a need for resynchronizing the telecommunications satellite.