Methods and apparatus for overlapping MIMO antenna physical sectors

• US 20070202809A1
• Filed: 02/21/2007
• Published: 08/30/2007
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Woodbury Wireless LLC
• Original Assignee: Rotani, Inc.
• Inventors: Spenik, John, Woodbury, Brian, Lastinger, Roc
• Granted Patent: US 8,009,646 B2
• Time in Patent Office: Days
• US Class Current: 455/63.400
• CPC Class Codes: H04B 17/15 Performance testing
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0495 using overlapping sectors in the same base station to implement MIMO for antennas

Abstract

Methods and apparatus for positioning antennas of a first wireless cell to form MIMO physical sectors and MIMO virtual sectors. Selecting a MIMO virtual sector for communication responsive to throughput, data throughput, signal-to-noise ratio, signal error rate, data error rate, retransmission requests, interference, rejection of multipath signals, transmission rate, and signal strength.

Claims

1. A first wireless cell that provides overlapping MIMO physical sectors positioned at different orientations, the first wireless cell comprising:

at least four antennas that each transmits and receives radio signals within a respective physical sector, each one antenna belongs to at most one group of at least two groups, each one group comprises at least two antennas of the first wireless cell, the antennas of each one group are positioned in such a way that the physical sector of each one antenna of each one group partially overlaps the physical sector of all the other antennas of the same group, each one group is positioned in such a way that the physical sector of at least one antenna of each one group at least partially overlaps the physical sector of at least one antenna of at least one other group, wherein a MIMO physical sector is formed in the area where the physical sectors of at least two antennas overlap, and wherein in each one MIMO physical sector at least two antennas operate as a MIMO antenna.

2. The first wireless cell of claim 1 wherein the physical sector of each one antenna of each one group substantially overlaps the physical sector of all the other antennas of the same group.

3. The first wireless cell of claim 1 comprising two groups wherein the physical sector of each one antenna of each one group partially overlaps the physical sector of all but one antenna of the other group.

4. The first wireless cell of claim 1 wherein the physical sector of one antenna of each one group partially overlaps the physical sector of all but one antenna of one other group.

5. The first wireless cell of claim 1 wherein the first wireless cell communicates using only one MIMO physical sector at any one time.

6. The first wireless cell of claim 1 wherein all antennas are assigned the same channel.

7. The first wireless cell of claim 1 comprising six antennas, a first group and a second group, wherein three antennas belong to each group, wherein each antenna has an angle of coverage of about 180 degrees, wherein the antennas of each one group are designated a first antenna, a second antenna and a third antenna of that group, wherein the physical sector of the first antenna of the first group does not substantially overlap the physical sector of the first antenna of the second group, wherein the physical sector of the second antenna of the first group does not substantially overlap the physical sector of the second antenna of the second group, wherein the physical sector of the third antenna of the first group does not substantially overlap the physical sector of the third antenna of the second group, wherein the physical sector of the second antenna of the first group overlaps the physical sector of the first antenna of the first group by about 120 degrees and the physical sector of the first antenna of the second group by about 60 degrees, wherein the physical sector of the second antenna of the second group overlaps the physical sector of the first antenna of the second group by about 120 degrees and the physical sector of the first antenna of the first group by about 60 degrees, wherein the physical sector of the third antenna of the first group overlaps the physical sector of the first antenna of the first group by about 60 degrees and the physical sector of the first antenna of the second group by about 120 degrees, wherein the physical sector of the third antenna of the second group overlaps the physical sector of the first antenna of the second group by about 60 degrees and the physical sector of the first antenna of the first group by about 120 degrees.

8. The first wireless cell of claim 7 wherein one first antenna, one second antenna, and one third antenna from any group whose physical sectors overlap in the same about 60 degree area operate as a MIMO antenna.

9. The first wireless cell of claim 1 comprising nine antennas, a first group, a second group, and a third group, wherein three antennas belong to each group, wherein each antenna has an angle of coverage of about 120 degrees, wherein the antennas of each one group are designated a first antenna, a second antenna and a third antenna of that group, wherein the physical sector of the first antenna of each one group does not substantially overlap the physical sector of the first antenna of any other group, wherein the physical sector of the second antenna of each one group does not substantially overlap the physical sector of the second antenna of any other group, wherein the physical sector of the third antenna of each one group does not substantially overlap the physical sector of the third antenna of any other group, wherein the physical sector of the second antenna of the first group overlaps the physical sector of the first antenna of the first group by about 80 degrees and the physical sector of the first antenna of the second group by about 40 degrees, wherein the physical sector of the second antenna of the second group overlaps the physical sector of the first antenna of the second group by about 80 degrees and the physical sector of the first antenna of the third group by about 40 degrees, wherein the physical sector of the second antenna of the third group overlaps the physical sector of the first antenna of the third group by about 80 degrees and the physical sector of the first antenna of the first group by about 40 degrees, wherein the physical sector of the third antenna of the first group overlaps the physical sector of the first antenna of the first group by about 40 degrees and the physical sector of the first antenna of the second group by about 80 degrees, wherein the physical sector of the third antenna of the second group overlaps the physical sector of the first antenna of the second group by about 40 degrees and the physical sector of the first antenna of the third group by about 80 degrees, wherein the physical sector of the third antenna of the third group overlaps the physical sector of the first antenna of the third group by about 40 degrees and the physical sector of the first antenna of the first group by about 80 degrees.

10. The first wireless cell of claim 9 wherein one first antenna, one second antenna, and one third antenna from any group whose physical sectors overlap in the same about 40 degree area operate as a MIMO antenna.

11. A method performed by a first wireless cell for reducing interference, the method comprising:

measuring performance through each MIMO antenna of the first wireless cell, wherein the first wireless cell comprises at least four antennas that each transmits and receives radio signals within a respective physical sector, each one antenna of the first wireless cell belongs to at most one group of at least two groups, each one group comprises at least two antennas of the first wireless cell, the antennas of each one group are positioned in such a way that the physical sector of each one antenna of each one group partially overlaps the physical sector of all the other antennas of the same group, each one group is positioned in such a way that the physical sector of at least one antenna of each one group at least partially overlaps the physical sector of at least one antenna of at least one other group, wherein a MIMO physical sector is formed in the area where the physical sectors of at least two antennas overlap, wherein in each one MIMO physical sector at least two antennas operate as a MIMO antenna;

selecting one MIMO antenna that provides improved performance; and

communicating through the selected MIMO antenna.

12. The first wireless cell of claim 11 wherein the physical sector of each one antenna of each one group substantially overlaps the physical sector of all the other antennas of the same group.

13. The method of 11 wherein measuring comprises measuring performance through each one MIMO antenna using all available channels.

14. The method of 11 wherein measuring comprises measuring at least one of throughput, data throughput, signal-to-noise ratio, signal error rate, data error rate, retransmission requests, interference, rejection of multipath signals, transmission rate, and signal strength.

15. A method for providing overlapping MIMO physical sectors of a first wireless cell positioned at different orientations, the method comprising:

appointing each one antenna of the first wireless cell to at most one group, wherein the first wireless cell comprises at least four antennas that each transmits and receives radio signals within a respective physical sector, each one antenna of the first wireless cell belongs to at most one group of at least two groups, each one group comprises at least two antennas of the first wireless cell;

positioning the antennas of each one group in such a way that the physical sector of each one antenna of each one group partially overlaps the physical sector of all the other antennas of the same group; and

positioning each one group in such a way that the physical sector of at least one antenna of each one group at least partially overlaps the physical sector of at least one antenna of at least one other group, wherein a MIMO physical sector is formed in the area where the physical sectors of at least two antennas overlap, wherein in each one MIMO physical sector at least two antennas operate as a MIMO antenna.

16. The method of 15 wherein positioning the antennas of each one group further comprises positioning the antennas of each one group in such a way that the physical sector of each one antenna of each one group substantially overlaps the physical sector of all the other antennas of the same group.

17. The method of 15 wherein positioning each one group further comprises positioning each one group in such a way that the physical sector of each one antenna of each one group partially overlaps the physical sector of all but one antenna of one other group.

18. The method of 15 wherein positioning each one group further comprises positioning each one group in such a way that the physical sector of one antenna of each one group partially overlaps the physical sector of all but one antenna of one other group.

19. The method of 15 further comprising measuring performance through each one MIMO physical sector.

20. The method of 19 wherein measuring comprises measuring at least one of throughput, data throughput, signal-to-noise ratio, signal error rate, data error rate, retransmission requests, interference, rejection of multipath signals, transmission rate, and signal strength.

21. The method of 15 wherein all antennas are assigned the same channel.

22. The method of 15 further comprising communicating using only one MIMO physical sector at any one time.

23. A first wireless cell that provides overlapping MIMO physical sectors, the first wireless cell comprising:

at least eight antennas that each transmits and receives radio signals within a respective physical sector, each one antenna belongs to at most one antenna group of at least four antenna groups, each one antenna group comprises at least two antennas of the first wireless cell, the antennas of each one antenna group are positioned in such a way that the physical sector of each one antenna substantially overlaps the physical sector of all the other antennas of the same antenna group, the antennas of each one antenna group operate as a MIMO antenna, each one antenna group belongs to at most one radio group of at least two radios groups, each one radio group comprises at least two antenna groups, each one antenna group is positioned in such a way that the physical sectors of the antennas of the each one antenna group do not overlap the physical sectors of the antennas of any other antenna group of the same radio group, the antennas of each one radio group are assigned the same channel, at least one antenna group of each one radio group is positioned in such a way that the physical sectors of the antennas of at least one antenna group at least partially overlap the physical sectors of the antennas of at least one antenna group of a different radio group, each antenna group of different radio groups whose physical sectors overlap are assigned different channels.

24. The first wireless cell of claim 23 wherein the physical sectors of the antennas of each one antenna group of each one radio group at least partially overlap the physical sectors of the antennas of at least one antenna group of a different radio group.

25. The first wireless cell of claim 23 comprising eight antennas, a first antenna group and a second antenna group that each belong to a first radio group, a third antenna group and a fourth antenna group that each belong to a second radio group.

26. The first wireless cell of claim 25 wherein the physical sectors of the antennas of the first antenna group substantially overlap the physical sectors of the antennas of the third antenna group, and wherein the physical sectors of the antennas of the second antenna group substantially overlap the physical sectors of the antennas of the fourth antenna group.

27. The first wireless cell of claim 25 wherein the physical sectors of the antennas of the first antenna group and the second antenna group at least partially overlap the physical sectors of the antennas of the third antenna group and fourth antenna group.

28. A method for forming overlapping MIMO physical sectors of a first wireless cell, the method comprising:

appointing each one antenna of the first wireless cell to at most one antenna group, wherein the first wireless cell comprises at least eight directional antennas that each transmits and receives radio signals within a respective physical sector, each one antenna belongs to at most one antenna group of at least four antenna groups, each one antenna group comprises at least two antennas of the first wireless cell;

positioning the antennas of each one antenna group in such a way that the physical sector of each one antenna substantially overlaps the physical sector of all the other antennas of the same antenna group, wherein the antennas of each one antenna group operate as a MIMO antenna;

appointing each one antenna group to at most one radio group of at least two radios groups, wherein each one radio group comprises at least two antenna groups;

positioning each one antenna group in such a way that the physical sectors of the antennas of the each one antenna group do not overlap the physical sectors of the antennas of any other antenna group of the same radio group;

positioning at least one antenna group of each one radio group in such a way that the physical sectors of the antennas of at least one antenna group of each one radio group at least partially overlap the physical sectors of the antennas of at least one antenna group of a different radio group;

assigning the same channel to each antenna of each one radio group; and

assigning different channels to each antenna group of different radio groups whose physical sectors overlap.

29. The method of 28 further comprising measuring performance through each one MIMO antenna using all available channels.

30. The method of 29 wherein measuring comprises measuring at least one of throughput, data throughput, signal-to-noise ratio, signal error rate, data error rate, retransmission requests, interference, rejection of multipath signals, transmission rate, and signal strength.

31. The method of 29 wherein assigning a same channel and assigning a different channel is done in accordance with measuring performance, wherein the channels are assigned to provide performance greater than a threshold performance.

32. The method of 28 further comprising selecting the MIMO antenna that provides an improved performance and communicating through the selected MIMO antenna.