DISTRIBUTED ANTENNA SYSTEM FOR MIMO SIGNALS

• US 20110135308A1
• Filed: 12/09/2009
• Published: 06/09/2011
• Est. Priority Date: 12/09/2009
• Status: Active Grant

• Current Assignee: Andrew Wireless Systems GmbH (CommScope Holding Company, Inc.)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Tarlazzi, Luigi, Faccin, Pier, Brighenti, Samuele
• Granted Patent: US 8,396,368 B2
• Time in Patent Office: Days
• US Class Current: 398/79
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0682 using phase diversity (e.g. phase sweeping)
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/028 WDM bus architectures
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A distributed antenna system (DAS) includes a multiple-input and multiple-output (“MIMO”) base station configured to output at least a first and second signal, and a hybrid coupler coupled thereto, the coupler configured to receive the first and second signal from the MIMO base station on respective first and second ports and provide an output signal on at least one output port, the output signal including at least a portion of the first signal and at least a portion of the second signal. The DAS further includes a master unit communicating with the coupler and configured to receive at least the output signal, and at least one remote unit communicating with the master unit and configured to communicate the output signal to a device.

Claims

1. A system comprising:

a multiple-input and multiple-output (MIMO) base station configured to output at least a first signal and a second signal;

a hybrid coupler coupled to the MIMO base station, the coupler configured to receive the first signal and the second signal from the MIMO base station on respective first and second ports and provide an output signal on at least one output port, the output signal including at least a portion of the first signal and at least a portion of the second signal;

at least one master unit communicating with the coupler and configured to receive at least the output signal of the coupler; and

at least one remote unit communicating with the master unit and configured to communicate the output signal to a device.

2. The system of claim 1, wherein the remote unit communicates with the master unit over an optical link.

3. The system of claim 2, wherein the optical link comprises:

a first optical fiber for carrying uplink signals; and

a second optical fiber for carrying downlink signals,

wherein the first and second optical fibers are configured as half duplex channels.

4. The system of claim 2, wherein the optical link comprises:

an optical fiber for carrying uplink and downlink signals on different wavelengths; and

a wavelength division multiplexer configured to combine or split the uplink and downlink signals on the optical fiber.

5. The system of claim 1, wherein the remote unit communicates with the master unit over a high data rate media selected from a group consisting of a coaxial cable, twisted pair copper wires, free space RF, shared networks, and combinations thereof.

6. The system of claim 5, wherein the shared networks are selected from a group consisting of Ethernet, SONET, SDH, ATM, PDH, and combination thereof.

7. The system of claim 2, wherein the optical link carries at least one of a modulated digital signal or a radio-over-fiber (RoF) signal.

8. The system of claim 1, wherein the coupler is a 90°

3 dB hybrid coupler.

9. The system of claim 8, wherein the coupler is further configured to output a plurality of output signals on a plurality of output ports, each of the plurality of output signals including at least a portion of the first signal and at least a portion of the second signal.

10. The system of claim 9, wherein at least one of the portions of the first and second signals making up the plurality of output signals is phase shifted.

11. The system of claim 9, a plurality of master units further configured to receive the plurality of output signals, the system further comprising:

a plurality of additional remote units communicating with the plurality of master units.

12. The system of claim 1, wherein at least one of the portion of the first signal or portion of the second signal is phase shifted orthogonally in relation to the respective first signal and second signal.

13. The system of claim 1 further comprising a SISO base station, the SISO base station being selectively coupled with the master unit and providing a SISO output signal.

14. The system of claim 13, wherein remote unit is further configured to communicate the output signal from the SISO base station simultaneously with the output signal of the MIMO base station.

15. The system of claim 13, wherein the system may be selectively operated in a SISO mode of operation or a MIMO mode of operation, wherein, in the SISO mode of operation, the master unit and remote unit handle SISO output signals and in the MIMO mode of operation the master unit and remote unit handle MIMO output signals.

16. The system of claim 1, wherein the remote unit is configured to communicate the output signal to a device with an air interface that includes at least one of an antenna and a radiating cable.

17. A system comprising:

a multiple-input and multiple-output (MIMO) base station configured to output at least a first signal and a second signal;

a selectively activatable hybrid coupler coupled to the MIMO base station, the coupler configured to receive the first signal and the second signal from the MIMO base station on respective first and second ports and provide a first output signal on at least one output port when activated, the first output signal including at least a portion of the first signal and at least a portion of the second signal;

a single-input and single-output (SISO) base station configured to output a second output signal on at least a second output port;

a summing circuit communicating with the coupler and the SISO base station, the summing circuit configured to combine the first and second output signals and provide a combined output signal;

at least one master unit communicating with the summing circuit and configured to receive at least the combined output signal; and

at least one remote unit communicating with the master unit and configured to communicate at least the combined output signal communicate the output signal to a device.

18. A method for transmitting signals through a distributed system comprising:

providing at least a first MIMO signal and a second MIMO signal;

delivering the first and second MIMO signals to respective first and second ports of a hybrid coupler;

providing an output signal on at least one output port of the coupler, the output signal including at least a portion of the first signal and at least a portion of the second signal;

directing the output signal to at least one master unit communicating with the coupler;

forwarding the output signal to at least one remote unit communicating with the master unit and communicating the output signal to a device from the remote unit.

19. The method of claim 18 wherein the remote unit communicates with the master unit over an optical link.

20. The method of claim 18 wherein the remote unit communicates with the master unit over a high data rate media selected from a group consisting of a coaxial cable, twisted pair copper wires, free space RF, shared networks, and combinations thereof.