Communication device and a method for determining an information from another apparatus

1. A communication device configured to determine an information from a second device comprising:

a radio frequency antenna comprising a plurality of antenna ports configured to receive a signal from the second device;

a baseband modem configured to

set an initial beamforming pattern, wherein the initial beamforming pattern comprises a beamforming direction and a corresponding beamforming area from each of the plurality of antenna ports, comprising determining a concerned direction interval based on overlapping beamforming areas of adjacent pairs of the plurality of antenna ports, and upon setting the initial beamforming pattern, determine a function for a relationship of signal gains for each pair of adjacent antenna ports and a position within the concerned direction interval for each pair of adjacent antenna ports, wherein the function is monotonic;

measure a signal gain from the signal on each of the plurality of antenna ports;

determine which concerned direction interval the second device occupies based on an antenna port having a highest signal gain and on one of the adjacent pair of antenna ports to the antenna port having the highest signal gain having a higher signal gain; and

determine the information from the second device based on the determined concerned direction interval.

2. The communication device of claim 1 , wherein the information is a channel direction information (CDI).

3. The communication device of claim 1 , wherein the concerned direction interval for each pair of adjacent antenna ports comprises a first beamforming area of a first antenna port of the pair overlapping on a portion of a second beamforming area of a second antenna port of the pair.

4. The communication device of claim 3 , further comprising wherein the concerned direction interval for each pair of adjacent antenna ports comprises an area in which the first antenna port of a pair of antenna ports and the second antenna port of a pair of antenna ports account for the highest signal gain and the higher signal gain within the concerned direction interval.

5. The communication device of claim 1 , wherein each beamforming area comprises a main lobe.

6. The communication device of claim 5 , wherein overlapping of adjacent beamforming areas comprises one of the adjacent beamforming areas overlapping on at least one half of the main lobe of its adjacent beamforming area.

7. The communication device of claim 1 , wherein the relationship of signal gains for each pair of adjacent antenna ports comprises a difference-to-sum ratio of the signal gains of the adjacent antenna ports.

8. The communication device of claim 7 , the baseband modem further configured to:

compute a difference-to-sum ratio of the highest signal gain and the higher signal gain of the pair of adjacent antenna ports; and

use the difference-to-sum ratio and the function to determine the information.

9. The communication device of claim 8 , the baseband modem further configured to update the beamforming pattern based on the acquired information in order to maximize the signal gain on at least one of the plurality of antenna ports.

10. A communication device configured to update a beamforming pattern, comprising:

a radio frequency antenna comprising a plurality of antenna ports configured to receive a signal from a second device; and

a baseband modem configured to:

set an initial beamforming direction from each of the plurality of antenna ports, wherein each beamforming direction has a beamforming coverage area, wherein beamforming coverage areas of antenna ports with adjacent beamforming directions overlap each other to form a concerned direction interval, and upon setting the initial beamforming pattern, determine a function for a relationship of signal gains for each pair of antenna ports with adjacent beamforming directions and a position within the concerned direction interval for each pair of antenna ports with adjacent beamforming directions, wherein the function is monotonic;

measure a signal gain from the signal on each of the plurality of antenna ports;

determine an antenna port having the highest signal gain;

compare the signal gains of the two antenna ports with beamforming directions adjacent to the antenna port with the highest signal gain and selecting the higher signal gain of the two compared antenna ports;

use the highest signal gain and the higher signal gain of the two compared antenna ports to determine a location of the second device; and

update the beamforming pattern.

11. The communication device of claim 10 , the baseband modem being further configured to:

compute a difference-to-sum ratio of the highest signal gain and the higher signal gain of the two compared antenna ports; and

use the difference-to-sum ratio and the function to determine the location of the other apparatus.

12. A method for a communication device with a plurality of antenna ports to determine an information from a second device comprising:

setting an initial beamforming pattern, wherein the initial beamforming pattern comprises a beamforming direction and a corresponding beamforming area for each of the plurality of antenna ports, comprising determining a concerned direction interval based on overlapping beamforming areas of adjacent pairs of the plurality of antenna ports;

determining a function for a relationship of signal gains for each pair of adjacent antenna ports and a position within the concerned direction interval for each pair of adjacent antenna ports, wherein the function is monotonic;

receiving a signal from the second device;

measuring a signal gain from the signal on each of the plurality of antenna ports;

determining which concerned direction interval the second device occupies based on an antenna port having the highest signal gain and on one of the adjacent pair of antenna ports to the antenna port having the highest signal gain having a higher signal gain; and

determining the information from the second device based on the determined concerned direction interval.

13. The method of claim 12 , further comprising wherein the concerned direction interval for each pair of adjacent antenna ports comprises a first beamforming area of a first antenna port of the pair overlapping on a portion of a second beamforming area of a second antenna port of the pair.

14. The method of claim 13 , further comprising wherein the concerned direction interval for each pair of adjacent antenna ports comprises an area in which the first antenna port of a pair of antenna ports and the second antenna port of a pair of antenna ports account for the highest signal gain and the higher signal gain within the concerned direction interval.

15. The method of claim 12 , wherein the relationship of signal gains for each pair of adjacent antenna ports comprises a difference-to-sum ratio of the signal gains of the adjacent antenna ports.

16. The method of claim 12 , further comprising:

computing a difference-to-sum ratio of the highest signal gain and the higher signal gain of the pair of adjacent antenna ports; and

using the difference-to-sum ratio and the function to determine the information.

17. The method of claim 16 , further comprising updating the beamforming pattern based on the acquired information in order to maximize the signal gain on at least one of the plurality of antenna ports.

18. A method for a communication device with a plurality of antenna ports to update a beamforming pattern, comprising:

setting an initial beamforming direction for each of the plurality of antenna ports, wherein each beamforming direction has a beamforming coverage area, wherein beamforming coverage areas of antenna ports with adjacent beamforming directions overlap each other to form a concerned direction interval;

determining a function for a relationship of signal gains for each pair of adjacent antenna ports having adjacent beamforming directions and a position within the concerned direction interval for each pair of antenna ports having adjacent beamforming directions, wherein the function is monotonic;

receiving a signal from a second device and measuring a signal gain from the signal on each of the plurality of antenna ports;

determining an antenna port having the highest signal gain;

comparing signal gains of the two antenna ports with beamforming directions adjacent to the antenna port having the highest signal gain and selecting the higher signal gain of the two compared antenna ports;

using the highest signal gain and the higher signal gain of the pair of compared signal gains to determine a location of the second device; and

updating the beamforming pattern.