SYSTEM AND METHOD FOR DISTRIBUTED ANTENNA WIRELESS COMMUNICATIONS

• US 20170054482A1
• Filed: 11/01/2016
• Published: 02/23/2017
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Rearden, LLC
• Original Assignee: Rearden, LLC
• Inventors: Forenza, Antonio, Perlman, Stephen G.
• Granted Patent: US 10,985,811 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

A system and method are described for distributed antenna wireless communications. For example, a method implemented within a wireless transmission system comprised of a plurality of wireless client devices and a plurality of distributed antennas is described comprising: computing channel state information (CSI) for wireless communication channels between the plurality of base distributed antennas and the wireless client devices; computing precoding weights from the channel state information; precoding data using the precoding weights prior to wireless transmission from the plurality of distributed antennas to the wireless client devices; and wirelessly transmitting the precoded data from the distributed antennas to each of the wireless client devices, wherein the precoding causes radio frequency interference between the plurality of base stations but simultaneously generating a plurality of non-interfering radio frequency user channels between the plurality of distributed antennas and the plurality of wireless client devices.

Claims

1. A multiuser multiple antenna system (MU-MAS) comprising:

a plurality of user devices each having at least one antenna; and

one or a plurality of wireless transceiver stations creating a plurality of concurrent and independent wireless links with the plurality of user devices,

wherein the wireless transceiver stations are equipped with a number of antennas far in excess of the number of antennas at least one user device.

2. The system as in claim 1 wherein the wireless links have a specified wavelength and wherein the antennas are spaced apart at a fraction of the wavelength.

3. The system as in claim 1 wherein one or a subset of the antennas are cross-polarized.

4. The system as in claim 1 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on at least one user device

5. The system as in claim 1 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on each user device.

7. The system as in claim 5 wherein the client devices are equipped with multiple antennas.

8. The system as in claim 5 wherein the client devices are equipped with a single antenna.

9. The system as in claim 5 wherein the antennas on the wireless transceiver stations are directional antennas.

10. The system as in claim 5 wherein the antennas are a phased array implementing beam-steering.

11. The system as in claim 5 wherein beamforming comprises creating multiple simultaneous beams at once.

12. The system as in claim 5 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on at least one user device.

13. The system as in claim 5 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on each user device.

15. The system as in claim 12 wherein exploiting channel reciprocity comprises estimating the uplink CSI and using it to derive the downlink CSI.

16. The system as in claim 12 wherein the CSI is estimated by using pilot tones, channel sounding or training signals.

18. The system as in claim 12 wherein the CSI is stored in a channel characterization matrix.

19. The system as in claim 16 wherein the channel characterization matrix comprises phase and amplitude of the channel.

21. The system as in claim 18 wherein the transmissions from the client devices are synchronized.

22. The system as in claim 12 wherein the CSI is continually or periodically updated.

23. The system as in claim 12 wherein the CSI changes as the user devices move from one location to another, and the CSI is updated.

24. The system as in claim 12 wherein the data links are created via precoding based on the CSI estimates.

25. The system as in claim 12 wherein the user devices are divided into groups.

26. The system as in claim 23 wherein the MU-MAS schedules different groups of users by cycling between groups.

27. The system as in claim 24 wherein the MU-MAS schedules the groups to assign the same or different levels of bandwidth to the user devices.

28. The system as in claim 24 wherein the MU-MAS schedules the groups based on relative proximity between the user devices.

29. The system as in claim 12 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on at least one user device.

30. The system as in claim 12 wherein the wireless transceiver stations are equipped with at least 10 times the number of antennas on each user device.

6. A multiuser wireless system comprising:

a plurality of user devices each having one or more antennas and being served concurrently over a plurality of wireless links, and

a plurality of wireless transceiver stations, each of the wireless transceiver stations having a number of antennas far in excess of the number of antennas on at least one user device,

the wireless system employing beamforming to increase link reliability or channel capacity.

14. A multiuser multiple antenna system (MU-MAS) comprising:

a plurality of wireless transceiver stations, each including a plurality of antennas; and

a plurality of user devices, each user device having one or more antennas, the wireless devices to establish concurrent wireless links with the wireless transceiver stations,

wherein there is a significant excess of antennas on each wireless transceiver station compared with the number of antennas on at least one user device,

wherein channel characterization data or channel state information (CSI) is estimated between the plurality of antennas on the wireless transceiver stations and the antennas of the plurality of user devices and channel reciprocity is exploited to create multiple non-interfering data links between the antennas of the wireless transceiver stations and the antennas of the user devices.

17. The system as in claim 14 wherein the training signals are orthogonal.

20. The system as in claim 14 wherein the training signals are transmitted by the client devices, and the wireless transceiver stations or antennas estimate the CSI.

31. A method implemented within a multiuser multiple antenna system (MU-MAS), comprising:

creating a plurality of concurrent and independent wireless links between a plurality of user devices and one or more wireless transceiver stations, wherein the wireless transceiver stations are equipped with a number of antennas far in excess of the number of antennas on each user device.

32. The method as in claim 31 wherein the wireless links have a specified wavelength and wherein the antennas are spaced apart a fraction of the wavelength.

33. The method as in claim 31 wherein one or a subset of the antennas are cross-polarized.

34. A method implemented within a multiuser wireless system comprising:

serving a plurality of user devices concurrently over a plurality of wireless links with one or more wireless transceiver stations, the user devices each having one or more antennas; and

wherein each of the wireless transceiver stations includes a number of antennas far in excess of the number of antennas on each user device, implementing beamforming to increase link reliability or channel capacity in links between the user devices and the one or more wireless transceiver stations.

35. The method as in claim 34 wherein the client devices are equipped with multiple antennas.

36. The method as in claim 34 wherein the client devices are equipped with a single antenna.

37. The method as in claim 34 wherein the antennas are directional antennas.

38. The method as in claim 34 wherein the antennas are a phased array implementing beam-steering.

39. The method as in claim 34 wherein beamforming comprises creating multiple simultaneous beams at once.

40. A method implemented within a multiuser multiple antenna system (MU-MAS) comprising of a plurality of wireless transceiver stations and a plurality of concurrently connected user devices, wherein there is a large excess of antennas compared with the user devices, the method comprising:

estimating the channel characterization data or channel state information (CSI) between the plurality of antennas of the wireless transceiver stations and the antennas of the plurality of user devices; and

exploiting channel reciprocity to create multiple non-interfering data links between the antennas of the wireless transceiver stations and the antennas of the user devices.

41. The method as in claim 40 wherein exploiting channel reciprocity comprises estimating the uplink CSI and using it to derive the downlink CSI.

42. The method as in claim 40 wherein the CSI is estimated by using pilot tones, channel sounding or training signals.

43. The method as in claim 42 wherein the training signals are orthogonal.

44. The method as in claim 40 wherein the CSI is stored in a channel characterization matrix.

45. The method as in claim 44 wherein the channel characterization matrix comprises phase and amplitude of the channel.

46. The method as in claim 40 wherein the training signals are transmitted by the client devices, and the wireless transceiver stations or antennas estimate the CSI.

47. The method as in claim 46 wherein the transmissions from the client devices are synchronized.

48. The method as in claim 40 wherein the CSI is continually or periodically updated.

49. The method as in claim 40 wherein the CSI changes as the user devices move from one location to another, and the CSI is updated.

50. The method as in claim 40 wherein the data links are created via precoding based on the CSI estimates.

51. The method as in claim 40 wherein the user devices are divided into groups.

52. The method as in claim 51 wherein the MU-MAS schedules different groups of users by cycling between groups.

53. The method as in claim 52 wherein the MU-MAS schedules the groups to assign the same or different levels of bandwidth to the user devices.

54. The method as in claim 52 wherein the MU-MAS schedules the groups based on relative proximity between the user devices.