Reducing location-dependent destructive interference in distributed antenna systems (DASS) operating in multiple-input, multiple-output (MIMO) configuration, and related components, systems, and methods

• US 10,256,879 B2
• Filed: 03/07/2018
• Issued: 04/09/2019
• Est. Priority Date: 07/30/2014
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: George, Jacob, Ng'Oma, Anthony, Yang, Hejie
• Primary Examiner(s): Cors, Nathan M
• Application Number:
  US15/914,088
• Publication Number:
  US 20180198498A1
• Time in Patent Office: 398 Days
• CPC Class Codes: H04B 10/2575 Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/25891 Transmission components H04B10/40 takes precedence
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0469 taking special antenna structures, e.g. cross polarized antennas into account
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

Components, systems, and methods for reducing location-dependent destructive interference in distributed antenna systems operating in multiple-input, multiple-output (MIMO) configuration are disclosed. Interference is defined as issues with received MIMO communications signals that can cause a MIMO algorithm to not be able to solve a channel matrix for MIMO communications signals received by MIMO receivers in client devices. These issues may be caused by lack of separation (i.e., phase, amplitude) in the received MIMO communications signals. Thus, to provide amplitude separation of received MIMO communications signals, multiple MIMO transmitters are each configured to employ multiple transmitter antennas, which are each configured to transmit in different polarization states. In certain embodiments, one of the MIMO communications signals is amplitude adjusted in one of the polarization states to provide amplitude separation between received MIMO communications signals. In other embodiments, multiple transmitter antennas in a MIMO transmitter can be offset to provide amplitude separation.

Claims

1. A method of transmitting multiple-input, multiple-output (MIMO) communications signals, the method comprising:

receiving a first optical downlink MIMO communications signal at a first amplitude over a first downlink communications medium;

converting the first optical downlink MIMO communications signal to a first electrical downlink MIMO communications signal;

transmitting the first electrical downlink MIMO communications signal over a first MIMO transmitter antenna in a first polarization;

receiving a second optical downlink MIMO communications signal at the first amplitude;

converting the second optical downlink MIMO communications signal to a second electrical downlink MIMO communications signal;

transmitting the second electrical downlink MIMO communications signal over a second MIMO transmitter antenna in a second polarization;

receiving a third optical downlink MIMO communications signal at the first amplitude;

converting the third optical downlink MIMO communications signal to a third electrical downlink MIMO communications signal;

transmitting the third electrical downlink MIMO communications signal over a third MIMO transmitter antenna in the first polarization;

receiving a fourth optical downlink MIMO communications signal;

converting the fourth optical downlink MIMO communications signal to a fourth electrical downlink MIMO communications signal; and

transmitting the fourth electrical downlink MIMO communications signal at a second amplitude, over a fourth MIMO transmitter antenna in the second polarization.

2. The method of claim 1, wherein:

transmitting the first electrical downlink MIMO communications signal comprises transmitting to a line-of-sight (LOS) wireless client; and

transmitting the second electrical downlink MIMO communications signal comprises transmitting to a LOS wireless client.

3. The method of claim 2, wherein:

transmitting the third electrical downlink MIMO communications signal comprises transmitting to a LOS wireless client; and

transmitting the fourth electrical downlink MIMO communications signal comprises transmitting to a LOS wireless client.

4. The method of claim 3, further comprising amplitude adjusting the fourth optical downlink MIMO communications signal.

5. The method of claim 4, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in a central unit.

6. The method of claim 4, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in the fourth downlink communications medium.

7. The method of claim 1, further comprising amplitude adjusting the fourth optical downlink MIMO communications signal.

8. The method of claim 7, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in a central unit.

9. The method of claim 7, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in the fourth downlink communications medium.

10. The method of claim 1, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in a central unit.

11. The method of claim 1, further comprising receiving the fourth optical downlink MIMO communications signal at the second amplitude modified from the first amplitude in the fourth downlink communications medium.