SYSTEMS AND METHODS FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS (OFDMA) COMMUNICATIONS OVER SATELLITE LINKS
First Claim
1. A method for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links, comprising:
- estimating a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between a user terminal in the spotbeam and a satellite;
estimating an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay; and
providing a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band.
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Accused Products
Abstract
Methods for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links. The methods include estimating a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between a user terminal in the spotbeam and a satellite, estimating an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay, and providing a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band. Corresponding systems and devices are also disclosed.
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Citations
69 Claims
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1. A method for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links, comprising:
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estimating a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between a user terminal in the spotbeam and a satellite; estimating an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay; and providing a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A system for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links, comprising:
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a satellite; a user terminal configured to communicate with the satellite via a satellite frequency over one of the satellite links, a scheduler configured to estimate a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between the user terminal in the spotbeam and the satellite, configured to estimate an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay, and configured to provide a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap at the user terminal between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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- 41. A scheduler for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links between a satellite and a user terminal, wherein the scheduler is configured to estimate a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between the user terminal in the spotbeam and the satellite, configured to estimate an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay, and configured to provide a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap at the user terminal between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band.
- 61. A radioterminal configured to communicate with a satellite using orthogonal frequency division multiple access (OFDMA) communications, wherein the radioterminal is configured to receive a designation of a guardband to be used for an OFDMA uplink frame transmitted by the radioterminal to the satellite, and wherein the radioterminal is configured not to transmit OFDMA signals during the uplink guardband so as to reduce an overlap between the OFDMA uplink frame and an OFDMA downlink frame.
Specification