System and method for canceling co-channel interference on-board a satellite

• US 8,780,787 B2
• Filed: 09/12/2012
• Issued: 07/15/2014
• Est. Priority Date: 09/12/2011
• Status: Expired due to Fees

• Current Assignee: Intelsat Corporation (Reorganized ISA SA)
• Original Assignee: Intelsat Corporation (Reorganized ISA SA)
• Inventors: Moreno, Daniel
• Primary Examiner(s): DEAN, RAYMOND S
• Application Number:
  US13/979,321
• Publication Number:
  US 20130303080A1
• Time in Patent Office: 671 Days
• Field of Search: 455/63.1, 455/67.13, 455/114.2, 455/296, 370/317
• US Class Current: 370/317
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18519 Operations control, administration or maintenance
• CPC Class Codes: H04J 11/004 using regenerative subtractive interference cancellation
• CPC Class Codes: H04J 11/005 of intercell interference

Abstract

Provided are systems and methods for minimizing co-channel interference on-board a satellite. An up-link signal received by the satellite is post-compensated, where the up-link signal includes a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter. The post-compensating includes identifying the interfering signal based on post-compensation parameters. In addition, a down-link signal to be transmitted from the satellite to a receiver is pre-compensated. The pre-compensation process includes determining gain relations between a gain of a first satellite antenna which transmits the down-link in a direction of the receiver and a gain of a second satellite antenna which transmits an interfering signal in the direction of the receiver, sampling and scaling interfering signals at the satellite based on the gain relations, and estimating a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver.

Claims

1. A method for minimizing co-channel interference on-board a satellite, the method comprising:

post-compensating of an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, the post-compensating comprising;

identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics;

determining gain relations between a satellite receiver antenna gain in a direction of the first transmitter and a satellite receiver antenna gain in a direction of the second transmitter;

sampling and scaling the interfering signal at the satellite based on the determined gain relations; and

estimating, based on the sampled and scaled interfering signal, a co-channel up-link interference component in the up-link signal,

wherein the post-compensated up-link signal is represented by

Z₁(t)=[DeltaR/R₂₂]·

Y₁(t),

where

DeltaR=(R₁₁·

R₂₂−

R₁₂·

R₂₁),

Y₁(t) is the desired signal transmitted by the first transmitter, R11 is the satellite receiver antenna gain in the direction of the first transmitter, R12 is the satellite receiver antenna gain in the direction of the second transmitter, R22 is an antenna gain of another satellite receiver in the direction of the second transmitter, and R21 is an antenna gain of the other satellite receiver in the direction of the first transmitter.

2. The method of claim 1, wherein the post-compensating further comprises:

subtracting the estimated co-channel up-link interference component from the up-link signal.

3. The method of claim 1, wherein the post-compensating further comprises:

multiplying a weight factor associated with the estimated co-channel up-link interference component with the up-link signal.

4. The method of claim 1, wherein the post-compensation parameters are stored in a database, wherein the post-compensation parameters are dynamically updated in response to changes in at least one of terrestrial networks, satellite configuration, or carrier operational parameters.

5. A method for minimizing co-channel interference on-board a satellite, the method comprising:

pre-compensating of a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensating comprising;

determining gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

sampling and scaling interfering signals at the satellite based on the determined gain relations; and

estimating a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the pre-compensated down-link signal is represented by;

S₁(t)=[DeltaT/T₂₂]·

Z₁(t),

where Z₁(t) is an up-link signal or a signal resulting from a previous post-compensation process and DeltaT=(T₁₁·

T₂₂−

T₁₂·

T₂₁),

T11 is the gain of the first satellite transmitter antenna in the direction of the receiver, T21 is the gain of the second satellite transmitter antenna in the direction of the receiver, T12 is a gain of the first satellite transmitter antenna in a direction of another receiver, and T22 is the gain of the second satellite transmitter antenna in the direction of the other receiver.

6. The method of claim 5, wherein the pre-compensating further comprises:

subtracting the estimated co-channel downlink interference component from the down-link signal.

7. The method of claim 5, wherein the pre-compensating further comprises:

multiplying a weight factor associated with the estimated co-channel downlink interference component with the down-link signal.

8. A method for minimizing co-channel interference on-board a satellite, the method comprising:

post-compensating of an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, the post-compensating comprising;

identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics;

determining gain relations between a satellite receiver antenna gain in a direction of the first transmitter and a satellite receiver antenna gain in a direction of the second transmitter,

sampling and scaling the interfering signal at the satellite based on the determined gain relations; and

estimating, based on the sampled and scaled interfering signal, a co-channel up-link interference component in the up-link signal; and

pre-compensating of a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensating comprising;

determining gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

sampling and scaling interfering signals at the satellite based on the determined gain relations; and

estimating a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the post-compensated up-link signal is represented by

Z₁(t)=[DeltaR/R₂₂]·

Y₁(t),

where DeltaR=(R₁₁·

R₂₂−

R₁₂·

R₂₁)

Y₁(t) is the desired signal transmitted by the first transmitter, R11 is the satellite receiver antenna gain in the direction of the first transmitter, R12 is the satellite receiver antenna gain in the direction of the second transmitter, R22 is an antenna gain of another satellite receiver in the direction of the second transmitter, and R21 is an antenna gain of the other satellite receiver in the direction of the first transmitter.

9. The method of claim 8, wherein the post-compensating further comprises:

subtracting the estimated co-channel up-link interference component from the up-link signal.

10. The method of claim 8, wherein the post-compensating further comprises:

multiplying a weight factor associated with the estimated co-channel up-link interference component with the up-link signal.

11. The method of claim 8, wherein the post-compensation parameters are stored in a database, wherein the post-compensation parameters are dynamically updated in response to changes in at least one of terrestrial networks, satellite configuration, or carrier operational parameters.

12. The method of claim 8, wherein the pre-compensating further comprises:

subtracting the estimated co-channel downlink interference component from the down-link signal.

13. The method of claim 8, wherein the pre-compensating further comprises:

multiplying a weight factor associated with the estimated co-channel downlink interference component with the down-link signal.

14. A method for minimizing co-channel interference on-board a satellite, the method comprising:

post-compensating of an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, the post-compensating comprising;

identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics; and

pre-compensating of a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensating comprising;

determining gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

sampling and scaling interfering signals at the satellite based on the determined gain relations; and

estimating a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the pre-compensated down-link signal is represented by;

S₁(t)=[DeltaT/T₂₂]·

Z₁(t),

where Z₁(t) is an up-link signal or a signal resulting from a previous post-compensation process and DeltaT=(T₁₁·

T₂₂−

T₁₂·

T₂₁),

T11 is the gain of the first satellite transmitter antenna in the direction of the receiver, T21 is the gain of the second satellite transmitter antenna in the direction of the receiver, T12 is a gain of the first satellite transmitter antenna in a direction of another receiver, and T22 is the gain of the second satellite transmitter antenna in the direction of the other receiver.

15. A system for minimizing co-channel interference on-board a satellite, the system comprising:

a post-compensation unit which post-compensates an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, wherein the post-compensation unit post-compensates the up-link signal by identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics,

wherein the post-compensation unit comprises;

a determination unit which determines gain relations between a satellite receiver antenna gain in a direction of the first transmitter and a satellite receiver antenna gain in a direction of the second transmitter;

a sampling unit which samples and scales the interfering signal at the satellite based on the determined gain relations; and

an estimating unit which estimates, based on the sampled and scaled interfering signal, a co-channel up-link interference component in the up-link signal,

wherein the post-compensation unit represents the post-compensated up-link signal by

Z₁(t)=[DeltaR/R₂₂]·

Y₁(t),

where DeltaR=(R₁₁·

R₂₂−

R₁₂·

R₁₁),

Y₁(t) is the desired signal transmitted by the first transmitter, R11 is the satellite receiver antenna gain in the direction of the first transmitter, R12 is the satellite receiver antenna gain in the direction of the second transmitter, R22 is an antenna gain of another satellite receiver in the direction of the second transmitter, and R21 is an antenna gain of the other satellite receiver in the direction of the first transmitter.

16. The system of claim 15, wherein the post-compensation unit further comprises:

a subtracting unit which subtracts the estimated co-channel up-link interference component from the up-link signal.

17. The system of claim 15, wherein the post-compensation unit further comprises:

a multiplication unit which multiplies a weight factor associated with the estimated co-channel up-link interference component with the up-link signal.

18. The system of claim 15, wherein the post-compensation parameters are stored in a database, wherein the post-compensation parameters are dynamically updated in response to changes in at least one of terrestrial networks, satellite configuration, or carrier operational parameters.

19. A system for minimizing co-channel interference on-board a satellite, the system comprising:

a pre-compensation unit which pre-compensates a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensation unit comprising;

a determination unit which determines gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

a sampling unit which samples and scales interfering signals at the satellite based on the determined gain relations; and

an estimating unit which estimates a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the pre-compensation unit represents the pre-compensated down-link signal by;

S₁(t)=[DeltaT/T₂₂]·

Z₁(t),

where Z₁(t) is an up-link signal or a signal resulting from a previous post-compensation process and DeltaT=(T₁₁·

T₂₂−

T₁₂·

T₂₁),

T11 is the gain of the first satellite transmitter antenna in the direction of the receiver, T21 is the gain of the second satellite transmitter antenna in the direction of the receiver, T12 is a gain of the first satellite transmitter antenna in a direction of another receiver, and T22 is the gain of the second satellite transmitter antenna in the direction of the other receiver.

20. The system of claim 19, wherein the pre-compensation unit further comprises:

a subtracting unit which subtracts the estimated co-channel downlink interference component from the down-link signal.

21. The system of claim 19, wherein the pre-compensating further comprises:

a multiplication unit which multiplies a weight factor associated with the estimated co-channel downlink interference component with the down-link signal.

22. A system for minimizing co-channel interference on-board a satellite, the system comprising:

a post-compensation unit which post-compensates an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, wherein the post-compensation unit post-compensates the up-link signal by identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics, wherein the post-compensation unit comprises;

a determination unit which determines gain relations between a satellite receiver antenna gain in a direction of the first transmitter and a satellite receiver antenna gain in a direction of the second transmitter;

a sampling unit which samples and scales the interfering signal at the satellite based on the determined gain relations; and

an estimating unit which estimates, based on the sampled and scaled interfering signal, a co-channel up-link interference component in the up-link signal; and

a pre-compensation unit which pre-compensates a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensation unit comprising;

a determination unit which determines gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

a sampling unit which samples and scales interfering signals at the satellite based on the determined gain relations; and

an estimating unit which estimates a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the post-compensation unit represents the post-compensated up-link signal by

Z₁(t)=[DeltaR/R₂₂]·

Y₁(t),

where DeltaR=(R₁₁·

R₂₂−

R₁₂·

R₂₁),

Y₁(t) is the desired signal transmitted by the first transmitter, R11 is the satellite receiver antenna gain in the direction of the first transmitter, R12 is the satellite receiver antenna gain in the direction of the second transmitter, R22 is an antenna gain of another satellite receiver in the direction of the second transmitter, and R21 is an antenna gain of the other satellite receiver in the direction of the first transmitter.

23. The system of claim 22, wherein the post-compensation unit further comprises:

a subtracting unit which subtracts the estimated co-channel up-link interference component from the up-link signal.

24. The system of claim 22, wherein the post-compensation unit further comprises:

a multiplication unit which multiplies a weight factor associated with the estimated co-channel up-link interference component with the up-link signal.

25. The system of claim 22, wherein the post-compensation parameters are stored in a database, wherein the post-compensation parameters are dynamically updated in response to changes in at least one of terrestrial networks, satellite configuration, or carrier operational parameters.

26. The system of claim 22, wherein the pre-compensation unit further comprises:

a subtracting unit which subtracts the estimated co-channel downlink interference component from the down-link signal.

27. The system of claim 22, wherein the pre-compensating further comprises:

a multiplication unit which multiplies a weight factor associated with the estimated co-channel downlink interference component with the down-link signal.

28. A system for minimizing co-channel interference on-board a satellite, the system comprising:

a post-compensation unit which post-compensates an up-link signal received by the satellite, the up-link signal comprising a desired signal transmitted by a first transmitter and an interfering signal transmitted by a second transmitter, wherein the post-compensation unit post-compensates the up-link signal by identifying the interfering signal based on post-compensation parameters including locations of the first transmitter and the second transmitter, carrier power levels of the desired signal and the interfering signal, and satellite antenna characteristics; and

a pre-compensation unit which pre-compensates a down-link signal to be transmitted from the satellite to a receiver, the down-link signal transmitted from a first satellite transmitter antenna and an interfering signal, which interferes with the down-link signal, transmitted from a second satellite transmitter antenna, the pre-compensation unit comprising;

a determination unit which determines gain relations between a gain of the first satellite transmitter antenna in a direction of the receiver and a gain of the second satellite transmitter antenna in the direction of the receiver;

a sampling unit which samples and scales interfering signals at the satellite based on the determined gain relations; and

an estimating unit which estimates a co-channel down-link interference component that the down-link signal is expected to experience on a path to the receiver,

wherein the pre-compensation unit represents the pre-compensated down-link signal by;

S₁(t)=[DeltaT/T₂₂]·

Z₁(t),

where Z₁(t) is an up-link signal or a signal resulting from a previous post-compensation process and DeltaT=(T₁₁·

T₂₂−

T₁₂·

T₂₁),

T11 is the gain of the first satellite transmitter antenna in the direction of the receiver, T21 is the gain of the second satellite transmitter antenna in the direction of the receiver, T12 is a gain of the first satellite transmitter antenna in a direction of another receiver, and T22 is the gain of the second satellite transmitter antenna in the direction of the other receiver.