Method and system for reducing interbeam interference and multipath fading in bent-pipe satellite communications systems
First Claim
1. A method of forming a communication link in a satellite communications system, the method comprising the steps of:
- receiving a plurality of communications signals at a satellite, each respective communications signal being transmitted from a transmitter of a group of transmitters, the group of transmitters being one of a plurality of groups of transmitters, each transmitter being associated with only one group, each respective communications signal being a code division multiple access signal having a predetermined code that is associated with the transmitter transmitting the communications signal, the predetermined code being selected from a first predetermined code set that is assigned to the group of transmitters with which the transmitter is grouped, each respective code set being different from other code sets associated with selected groups of transmitters so that the code sets are arranged in a code set pattern, the code set pattern being repeated for each selected group of transmitters;
grouping together communications signals received on a beam having a same predetermined code set;
despreading the communications signals; and
respreading the communications signals using a second predetermined code set.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system of forming and processing communication links in a satellite communications system. The satellite communications system includes a plurality of groups of transmitters, a satellite and a plurality of destination receivers. Each transmitter is associated with only one transmitter group and transmits a communications signal. Each respective communications signal is a CDMA signal having a predetermined code that is associated with a transmitter. Each respective predetermined code is selected from a code set assigned to the group of transmitters with which the transmitter is grouped. Each code set is different from code sets associated with the transmitters of other selected transmitter groups so that the code sets are arranged in a code set pattern that is repeated for selected groups of transmitters. The satellite receives the communications signals and groups together each received communications signal having a same predetermined code set. The code sets of selected uplink communications signals in a group of received communications signals are fully or partially despread, filtered, and respread so that the group of communications signals contains communications signals from only one code set. Each group of communications signals is then transmitted to a different destination receiver, or groups on different code sets to the same destination receiver.
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Citations
33 Claims
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1. A method of forming a communication link in a satellite communications system, the method comprising the steps of:
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receiving a plurality of communications signals at a satellite, each respective communications signal being transmitted from a transmitter of a group of transmitters, the group of transmitters being one of a plurality of groups of transmitters, each transmitter being associated with only one group, each respective communications signal being a code division multiple access signal having a predetermined code that is associated with the transmitter transmitting the communications signal, the predetermined code being selected from a first predetermined code set that is assigned to the group of transmitters with which the transmitter is grouped, each respective code set being different from other code sets associated with selected groups of transmitters so that the code sets are arranged in a code set pattern, the code set pattern being repeated for each selected group of transmitters; grouping together communications signals received on a beam having a same predetermined code set; despreading the communications signals; and respreading the communications signals using a second predetermined code set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A satellite communications system comprising:
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a plurality of groups of transmitters, each transmitter transmitting a communications signal, each transmitter being associated with only one group, each respective communications signal being a code division multiple access signal having a predetermined code that is associated with the transmitter, the predetermined code being selected from a first predetermined code set that is assigned to the group of transmitters with which the transmitter is grouped, each respective code set being different from other code sets associated with the transmitters of other selected groups of transmitters so that the code sets are arranged in a code set pattern, the code set pattern being repeated for each selected group of transmitters; and a satellite receiving the communications signals, the satellite grouping together communications signals received on a beam having a same predetermined code set, despreading the communications signals, respreading the communications signals using a second predetermined code set, and transmitting each group of communications signals to a destination receiver. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification