DISTRIBUTED ANTENNA SYSTEM FOR MIMO COMMUNICATIONS

• US 20140269966A1
• Filed: 05/30/2014
• Published: 09/18/2014
• 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 9,413,439 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• 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 and apparatus for determining placement of a plurality of antennas of a distributed antenna system for handling MIMO signals includes, at a first location, simulating the communication of a first MIMO signal by a first remote unit over an air interface in an environment and, at a second location, simulating the communication of a second MIMO signal by a second remote unit over an air interface in the environment. The first and second locations are arranged within the environment to provide overlapping signal coverage of both the first MIMO signal and the second MIMO signal at a third location in the environment. Analysis is made of at least an imbalance of received power between the first and second MIMO signals within the environment at a third location in order to determine whether a desired capacity for MIMO communications with the system has been achieved at the third location.

Claims

1. A method for determining placement of a plurality of antennas of a distributed antenna system for handling MIMO signals in an environment comprising:

at a first location, simulating the communication of a first MIMO signal by a first remote unit over an air interface in the environment;

at a second location, simulating the communication of a second MIMO signal by a second remote unit over an air interface in the environment;

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

with a device having at least one processor, receiving the MIMO signals and analyzing at least an imbalance of received power between the first and second MIMO signals within the environment at a third location in order to determine whether a desired capacity for MIMO communications with the system has been achieved at the third location.

2. The method of claim 1 wherein the step of simulating the communication of a first MIMO signal or a second MIMO signal in the environment includes positioning a remote unit at a respective location within an environment and communicating the respective signal over the air interface.

3. The method of claim 1, further comprising:

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

4. The method of claim 3, further comprising:

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

5. The method of claim 4, further comprising:

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

6. The method of claim 5, further comprising:

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

adjusting the location of deployment of the simulation of at least one of the MIMO signals.

7. The method of claim 1, further comprising:

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

8. The method of claim 7, 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.

9. An apparatus for determining placement of a plurality of antennas of a distributed antenna system for handling MIMO signals, comprising:

circuitry for receiving a first MIMO signal over an air interface in an environment and determining the received power of the first MIMO signal;

circuitry for receiving a second MIMO signal over an air interface in an environment and determining the received power of the second MIMO signal;

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

at least one processor configured for analyzing at least an imbalance of received power between the first and second MIMO signals within the environment at the third location in order to determine whether a desired capacity for MIMO communications with the system has been achieved at the third location.

10. The apparatus of claim 9 wherein the processor is further configured for determining a signal-to-noise and interference ratio that is associated with at least one of the first or second MIMO signals.

11. The apparatus of claim 10 wherein the processor is further configured for determining, from the analyzed imbalance, a channel condition number associated with the system.

12. The apparatus of claim 11 wherein the processor is further configured for determining, from the signal-to-noise and interference ratio and the channel condition number, a capacity for the system.

13. The apparatus of claim 12 wherein the processor is further configured for comparing the capacity for the system to a predetermined capacity threshold.

14. The apparatus of claim 12 wherein the processor is further configured for accessing a datastore including capacity information.

15. The apparatus of claim 13 wherein the processor is further configured, in response to determining that the simulated imbalance is less than the predetermined threshold, for determining whether to one of increase or decrease the simulated imbalance

16. 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 MIMO 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 MIMO signals through the master unit;

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

a second set of remote units receiving the second MIMO signal different from the first MIMO signal received by the first remote units, the second set of remote units configured for being positioned at various locations within the environment different from the locations of the remote units of the first set, the remote units of the second set configured for communicating the second MIMO signal over air interfaces in the environment;

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

a device configured for receiving at least a first MIMO signal and at least a second MIMO signal and determining the received power of the first and second MIMO signals in at least one of the third locations;

the device further configured for analyzing at least an imbalance of received power between the first and second MIMO signals within the environment at the third location in order to determine whether a desired capacity for MIMO communications with the system has been achieved at that third location.

17. The distributed antenna system of claim 16 wherein the device is further configured for determining a signal-to-noise and interference ratio that is associated with at least one of the first or second MIMO signals.

18. The distributed antenna system of claim 17 wherein the device is further configured for determining, from the analyzed imbalance, a channel condition number associated with the system.

19. The distributed antenna system of claim 18 wherein the device is further configured for determining, from the signal-to-noise and interference ratio and the channel condition number, a capacity for the system.

20. The distributed antenna system of claim 19 wherein the device is further configured for comparing the capacity for the system to a predetermined capacity threshold.