Systems and Methods for Satellite Forward Link Transmit Diversity Using Orthagonal Space Coding
AssigneeACT Technologies, Inc.
InventorDunmin Zheng
Life of this patent
Estimating the term…
Abstract
Methods of transmitting communications signals from a satellite to a wireless terminal include determining a location of the wireless terminal, selecting a plurality of antenna feed elements at the satellite in response to the determined location of the wireless terminal, block coding a plurality of symbols into a number of transmit streams equal to the number of selected antenna feed elements, and transmitting the transmit streams over the selected plurality of antenna feed elements. Block coding the plurality of symbols may include space-code, space-time and/or space-frequency encoding the plurality of symbols. Related satellites, satellite gateways and satellite communications systems are also disclosed.
Claims73
A method of transmitting communications signals from a satellite to a wireless terminal, comprising:
- determining a location of the wireless terminal;
- selecting a plurality of antenna feed elements at the satellite in response to the determined location of the wireless terminal;
- block coding a plurality of symbols into a number of transmit streams equal to the number of selected antenna feed elements;
- and
- transmitting the transmit streams over the selected plurality of antenna feed elements.
18 The method of claim 16, wherein the transmission matrix has a form such that the product of the transmission matrix and its transpose conjugate is equal to the sum of the squares of the plurality of symbols used to generate the transmission matrix multiplied by a diagonal unity matrix.
A satellite configured to transmit communications signals to a wireless terminal, comprising:
- an antenna including a plurality of feed elements;
- a controller configured to obtain a location of the wireless terminal and configured to select a plurality of the antenna feed elements in response to the obtained location of the wireless terminal, and configured to block code a plurality of symbols into a number of transmit streams equal to the number of selected antenna feed elements;
- and
- a transmitter configured to transmit the transmit streams over the selected plurality of antenna feed elements.
A satellite gateway configured to transmit communications signals to a wireless terminal via a satellite including an antenna having a plurality of feed elements, comprising:
- a controller configured to obtain a location of the wireless terminal and configured to select a plurality of the antenna feed elements in response to the obtained location of the wireless terminal and configured to block code a plurality of symbols into a number of transmit streams equal to the number of selected antenna feed elements;
- and
- a transmitter configured to transmit the transmit streams to the satellite for transmission over the selected plurality of antenna feed elements.
A satellite communications system, comprising:
- a satellite including an antenna having a plurality of antenna feed elements;
- and
- a satellite gateway comprising:
- a controller configured to obtain a location of a wireless terminal within a geographic footprint of the satellite, and configured to select a plurality of the antenna feed elements in response to the obtained location of the wireless terminal and configured to block code a plurality of symbols into a number of transmit streams equal to the number of selected antenna feed elements;
- and
- a transmitter configured to transmit the transmit streams to the satellite for transmission over the selected plurality of antenna feed elements.
Dependencies are inferred from the claim text.