Radio communication using a plurality of selected antennas
The invention relates to a method for radio communication using a plurality of antennas, and to an apparatus for radio communication using a plurality of antennas. An apparatus for radio communication of the invention comprises: 4 antennas; a radio device; an antenna tuning apparatus having 2 antenna ports and 2 radio ports; a switching unit comprising 4 input ports each coupled to one of the antennas through a feeder, and 2 output ports, the switching unit operating in an active configuration in which it provides a path between any one of the output ports and one of the input ports, the active configuration being determined by a configuration instruction generated by the radio device; and a tuning control unit, the tuning control unit receiving a tuning instruction generated by the radio device, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus.
1. A method for radio communication by an apparatus including N antennas, the method comprising:
generating, by a radio communication unit, a configuration instruction and a tuning instruction, and transmitting, by the radio communication unit, the configuration instruction to a switch and the tuning instruction to a tuner;
selecting, by the switch comprising N input ports and n output ports, n antennas among the N antennas based on the configuration instruction, and providing, by the switch, a path between an output port of the selected n output ports and an input port of the N input ports, the input port being coupled to antennas of the n selected antennas, where N is an integer greater than or equal to 3, each of the N antennas to be operated at a frequency in a frequency band, n being an integer greater than or equal to 2 and less than or equal to N minus 1, each of the N input ports being coupled to one of the N antennas; and
coupling, by an antenna tuning apparatus comprising n antenna ports, m radio ports and p adjustable impedance devices, the n output ports to the n antenna ports, where m is an integer greater than or equal to 2 and where p is an integer greater than or equal to 2m and each of the p adjustable impedance devices has a reactance being adjustable based on the tuning instruction received from the tuner.
2. The method of claim 1 , wherein the path is a path between the output port of the n output ports and only one input port of the N input ports.
3. The method of claim 2 , wherein the antenna tuning apparatus includes each of n antenna tuning apparatus units comprising one of the n antenna ports, one of the m radio ports, or at least two adjustable impedance devices.
4. The method of claim 2 ,
wherein the tuning instruction comprises a function of one or more quantities indicating a channel matrix.
5. The method of claim 2 ,
wherein the tuning instruction is a function of q real quantities based on an impedance matrix of the m radio ports, where q is an integer greater than or equal to m.
6. The method of claim 2 , further comprising:
estimating, by a localizer, a plurality of localization variables to determine the configuration instruction,
wherein each of the localization variables is determined based on a distance between a part of a human body and a zone of the radio communication unit.
7. The method of claim 6 , wherein the configuration instruction is determined from a set of pre-defined configuration instructions stored in a lookup table, based on the localization variables and on frequencies used for the radio communication with the N antennas.
8. The method of claim 1 , wherein, when an impedance matrix of the n antenna ports is equal to a diagonal impedance matrix at the frequency in the frequency band, an impedance matrix of the m radio ports is determined based on a reactance of one of the p adjustable impedance devices.
9. The method claim 8 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices.
10. An apparatus comprising N antennas, the apparatus comprising:
the N antennas, where N is an integer greater than or equal to 3, each of the N antennas to be operated at a frequency in a frequency band;
at least one processor of a radio communication unit, configured to generate a configuration instruction and a tuning instruction, and transmit the configuration instruction to a switch and the tuning instruction to a tuner;
a switch comprising N input ports and n output ports, configured to select n antennas among the N antennas based on the configuration instruction, and provide a path between an output port of the selected n output ports and an input port of the N input ports, the input port being coupled to antennas of the n selected antennas, where n is an integer greater than or equal to 2 and less than or equal to N minus 1, each of the N input ports being coupled to one of the N antennas; and
an antenna tuning apparatus comprising n antenna ports, m radio ports and p adjustable impedance devices, configured to couple the n output ports to the n antenna ports, where m is an integer greater than or equal to 2, p is an integer greater than or equal to 2m, each of the p adjustable impedance devices has a reactance being adjustable based on the tuning instruction received from the tuner,
wherein the tuner is configured to:
receive the tuning instruction from the at least one processor, and transmit the tuning instruction to the antenna tuning apparatus.
11. The apparatus of claim 10 , wherein the path is a path between the output port of the n output ports only one input port of the N input ports.
12. The apparatus of claim 11 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices.
13. The apparatus of claim 12 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices.
14. The apparatus of claim 11 , wherein the antenna tuning apparatus each of n antenna tuning apparatus units comprising one of the n antenna ports, one of the m radio ports, or at least two adjustable impedance devices.
15. The apparatus of claim 11 , wherein the tuning instruction comprises a function of one or more quantities indicating a channel matrix.
16. The apparatus of claim 11 , wherein the tuning instruction being a function of q real quantities based on an impedance matrix of the m radio ports, where q is an integer greater than or equal to m.
17. The apparatus of claim 11 , further comprising:
a localizer configured to estimate a plurality of localization variables to determine the configuration instruction,
wherein each of the localization variables is determined based on a distance between a part of a human body and a zone of the radio communication unit.
18. The apparatus of claim 17 , wherein the configuration instruction is determined from a set of pre-defined configuration instructions stored in a lookup table, based on the localization variables and on the frequencies used for radio communication with the N antennas.