DISTRIBUTED ANTENNA SYSTEM FOR MIMO COMMUNICATIONS

• US 20110201368A1
• Filed: 02/11/2011
• Published: 08/18/2011
• Est. Priority Date: 02/12/2010
• 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
• Granted Patent: US 8,744,504 B2
• Time in Patent Office: Days
• US Class Current: 455/507
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0426 Power distribution
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

A method of deploying a distributed antenna system (DAS) is provided. The method comprises outputting first and second signals from a multiple-input and multiple-output base station (MIMO BTS) and coupling a master unit to the MIMO BTS. The method further comprises coupling first and second remote units to the master unit, the first remote unit communicating the first signal over a first air interface located within the environment at a first location, the second remote unit communicating the second signal over a second air interface within the environment at a second location. The first and second remote units are arranged at the first and second locations within the environment and configured to provide signal coverage of both the first signal and the second signal at a third location in the environment to provide the capacity for MIMO communications through the system at the third location.

Claims

1. A method of deploying a distributed antenna system, comprising:

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

coupling one or more master units to the MIMO base station for receiving the first and second signals;

coupling a first remote unit and a second remote unit to the one or more master units so that the first remote unit receives the first signal and the second remote unit receives the second signal;

positioning the first remote unit at a first location within an environment and communicating the first signal over a first air interface in the environment;

positioning the second remote unit at a second location within the environment and communicating the second signal over a second air interface in the environment;

the first and second remote units arranged at the first and second locations within the environment and configured to provide signal coverage of both the first signal and the second signal at a third location in the environment;

positioning the first and second remote units within the environment for achieving a desirable received power imbalance at the third location to provide the capacity for MIMO communications through the system at the third location.

2. The method of claim 1 further comprising coupling first and second master units to the MIMO base station, the first and second master units configured to receive the first and second signal, respectively, and coupling the first remote unit to the first master unit and coupling the second remote unit to the second master unit.

3. The method of claim 1 further comprising analyzing at least an imbalance of received power between the first and second signals determined within the environment at the third location to determine whether a predetermined capacity for MIMO communications with the system has been achieved at the third location.

4. The method of claim 1, further comprising:

determining, at the third location, a signal-to-noise and interference ratio associated with at least one of the first or second signals.

5. The method of claim 4 further comprising:

determining, from the imbalance, a channel condition number associated with the system.

6. The method of claim 5, further comprising:

determining, from the signal-to-noise and interference ratio and the channel condition number, a capacity for the system.

7. The method of claim 6, further comprising:

determining that the capacity for the distributed antenna system does not meet a predetermined capacity threshold; and

adjusting the location of deployment of at least one of the air interfaces.

8. The method of claim 1, further comprising:

determining whether the imbalance is less than a predetermined threshold.

9. The method of claim 8, further comprising:

in response to determining that the imbalance is less than the predetermined threshold, determining whether to increase the imbalance.

10. The method of claim 8, further comprising:

in response to determining that the imbalance is less than the predetermined threshold, determining that the capacity for the system does not meet a predetermined capacity threshold; and

adjusting the location of deployment of at least one of the air interfaces.

11. The method of claim 8, further comprising:

in response to determining that the imbalance is greater than the predetermined threshold, determining whether to decrease the imbalance.

12. The method of claim 7, wherein the predetermined threshold is about 15 dB.

13. The method of claim 1, wherein the first and second remote units are arranged in the first and second locations and configured so that the first and second air interfaces are interleaved within the environment to provide interleaved distribution of the first and second signals.

14. A method for determining placement of a plurality of antennas of a distributed antenna system with a computing system of the type that includes one or more processors and a memory, comprising:

simulating a first remote unit communicating a first signal over a first air interface located within an environment at a first location;

simulating a second remote unit communicating a second signal over a second interface located within an environment at a second location; and

analyzing at least a simulated imbalance of received power between the first and second signals determined within the environment at a third location to determine whether a predetermined capacity for MIMO communications with the system has been achieved.

15. The method of claim 14, further comprising:

determining, at the third location, a signal-to-noise and interference ratio associated with at least one of the first or second signals.

16. The method of claim 15, further comprising:

determining, from the simulated imbalance, a channel condition number associated with the system.

17. The method of claim 16, further comprising:

determining, from the signal-to-noise and interference ratio and the channel condition number, a capacity for the system.

18. The method of claim 17, further comprising:

determining that the capacity for the system does not meet a predetermined capacity threshold; and

adjusting the location of deployment of the at least one of the air interfaces.

19. The method of claim 18, further comprising:

determining whether the simulated imbalance is less than a predetermined threshold.

20. The method of claim 19, further comprising:

in response to determining that the simulated imbalance is less than the predetermined threshold, determining whether to one of increase or decrease the simulated imbalance.

21. A distributed antenna system comprising:

at least one master unit, the master unit configured for coupling with a multiple-input and multiple-output (MIMO) base station to receive first and second signals from the MIMO base station;

a plurality of remote units coupled with the master unit, the remote units configured to receive the first and second signals through the master unit;

a first set of remote units receiving the first signal and configured for being positioned at various locations within the an environment, the remote units of the first set configured for communicating the first signal over air interfaces in the environment;

a second set of remote units receiving the second signal and configured for being positioned at various locations within the an environment, the remote units of the second set configured for communicating the second signal over air interfaces in the environment;

the first and second sets of remote units arranged within the environment and configured to provide interleaved signal coverage of both the first signal and the second signal at a plurality of third locations in the environment;

the first and second remote units being positioned within the environment for achieving a desirable received power imbalance at the third location to provide the capacity for MIMO communications through the system at the third locations.

22. The distributed antenna system of claim 21 further comprising a wireless device configured for analyzing at least an imbalance of received power between the first and second signals determined within the environment at the third location to determine whether a predetermined capacity for MIMO communications with the system has been achieved at the third location.

23. The distributed antenna system of claim 21 wherein the remote units are arranged within the environment and configured to provide signal coverage of both the first signal and the second signal to provide, for at least one of the third locations, a desired imbalance of received power between the first and second signals.

24. The distributed antenna system of claim 23 wherein the remote units are arranged within the environment and configured to provide signal coverage of both the first signal and the second signal to provide, for at least one of the third locations, a desired a signal-to-noise and interference ratio associated with at least one of the first or second signals.

25. The distributed antenna system of claim 24 wherein the imbalance of received power is associated with a channel condition number associated with the system.

26. The distributed antenna system of claim 25 wherein the system has a capacity based on the signal-to-noise and interference ratio and the channel condition number, and the capacity for the system exceeds a predetermined capacity threshold.