Satellite MIMO system
A base station for communication with a terminal station having a plurality of terminal station antennas. The base station has a plurality of directional antennas, each of the plurality of directional antennas in communication with satellites in view. The base station also has a processing device (e.g., eNodeB) to transmit each of the multiple base-station antenna signals via each of the plurality of directional antennas to satellites and/or the beams of the same satellite seen by the terminal station for retransmission to the plurality of terminal station antennas.
1. A base station configured to communicate with a terminal station having a plurality of terminal station antennas, the base station comprising:
a set of directional antennas, each of the set of directional antennas configured for communication with one or more satellites that are in view of the terminal station, the communication including a first set of signals transmitted to the one or more satellites and a second set of signals received from the one or more satellites; and
a processing device operatively coupled to the set of directional antennas; the processing device being configured to:
adjust transmit times of physical resource blocks (PRBs) associated with the terminal station according to downlink arrival times for signals between the one or more satellites and the plurality of terminal station antennas so that a set of downlink signals from the one or more satellites to the terminal station are time aligned; and
cause the set of directional antennas to transmit the first set of signals to the one or more satellites and cause retransmission of the first set of signals as the set of downlink signals from the one or more satellites to the terminal station according to the adjusted transmit times of the PRBs;
wherein adjustment of the transmit times of the PRBs includes application of timing advances on each of the one or more satellites that are in view of the terminal station; and
wherein application of the timing advances is performed via different RF ports of the base station.
2. The base station of claim 1 , wherein the first set of signals includes a set of data streams, each data stream in the set corresponding to one of the set of directional antennas.
3. The base station of claim 2 , wherein each data stream in the set is the same.
4. The base station of claim 2 , wherein each data stream in the set is at a same frequency.
5. The base station of claim 2 , wherein each data stream in the set is at a different frequency.
6. The base station of claim 1 , wherein:
the one or more satellites is a plurality of satellites;
the processing device is configured to select a given one of the plurality of satellites as a reference satellite; and
the processing device is configured to adjust the transmit times of the PRBs associated with the other ones of the plurality of satellites relative to the reference satellite.
7. The base station of claim 1 , wherein:
the base station is configured to communicate with each of a plurality of terminal stations including the terminal station, via the one or more satellites that are in view of the plurality of terminal stations, each terminal station having a corresponding plurality of terminal station antennas; and
each terminal station of the plurality of terminal stations uses different PRBs than other ones of the plurality of terminal stations located in a same cell.
8. The base station of claim 7 , wherein the PRBs of each terminal station in the same cell are time adjusted depending on a physical location of each terminal station.
9. A base station configured to communicate with a plurality of terminal stations each having a corresponding plurality of terminal station antennas, the base station comprising:
a set of directional antennas, each of the set of directional antennas configured for communication with one or more satellites that are in view of the plurality of terminal stations, the communication including a first set of signals transmitted to the one or more satellites and a second set of signals received from the one or more satellites; and
a processing device operatively coupled to the set of directional antennas; the processing device being configured to:
adjust transmit times of physical resource blocks (PRBs) associated with each of the terminal stations according to downlink arrival times for signals between the one or more satellites and the corresponding pluralities of terminal station antennas so that a set of downlink signals from the one or more satellites to the plurality of terminal stations are time aligned; and
cause the set of directional antennas to transmit the first set of signals to the one or more satellites and cause retransmission of the first set of signals as the set of downlink signals from the one or more satellites to the plurality of terminal stations according to the adjusted transmit times of the PRBs;
wherein adjustment of the transmit times of the PRBs includes scheduling the PRBs with downlink timing advances for specific ones of the plurality of terminal stations in multiple input multiple output (MIMO) operation on different RF ports of the base station.