DISTRIBUTED ANTENNA SYSTEM FOR MIMO SIGNALS

• US 20130195467A1
• Filed: 03/12/2013
• Published: 08/01/2013
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Eisenwinter, Stefan, Braz, Oliver, Brighenti, Samuele, Mini, Massimiliano, Kummetz, Thomas, Schmid, Peter, Gunzner, Peter, Langer, Harald, Fabbri, Marianna, Fabbri, Enrico Maria, Parrucci, Marco
• Granted Patent: US 9,231,670 B2
• Time in Patent Office: Days
• US Class Current: 398/115
• CPC Class Codes: H04B 1/0096 where a full band is frequency converted into another full band
• CPC Class Codes: H04B 7/0413 MIMO systems

Abstract

A distributed antenna system includes a master unit configured to receive at least one set of multiple input multiple output (MIMO) channel signals from at least one signal source. The master unit is configured to frequency convert at least one of the MIMO channel signals to a different frequency from an original frequency, and combine the MIMO channel signals for transmission. An optical link couples the master unit with a remote for transceiving the MIMO channel signals. The remote unit is configured to receive the MIMO channel signals to be transmitted over antennas and includes an extension port configured to transceive at least one of the MIMO channel signals. An extension unit is coupled to the remote unit and is configured to frequency convert at least one of the first and second MIMO channel signals from the different frequency back to an original frequency for transmission over an antenna.

Claims

1. A distributed antenna system, comprising:

a master unit configured to receive at least one set of multiple input multiple output (MIMO) channel signals at an original frequency from at least one signal source, the MIMO channel signals including at least a first MIMO channel signal and a second MIMO channel signal, the master unit being configured to frequency convert at least one of the first and second MIMO channel signals to a different frequency from the original frequency, and combine the first MIMO channel signal with the second MIMO channel signal for transmission;

an optical link operably coupled with the master unit;

at least one remote unit in communication with the master unit via the optical link for transceiving the MIMO channel signals between the remote unit and the master unit, the remote unit including at least one extension port configured to transceive at least one of the MIMO channel signals; and

an extension unit coupled to the at least one remote unit at the extension port, the extension unit being configured to receive at least one of the first and second MIMO channel signals and to frequency convert at least one of the first and second MIMO channel signals from the different frequency back to the original frequency for transmission over one or more antennas.

2. The distributed antenna system of claim 1 wherein the master unit is configured to frequency convert both of the first and second MIMO channel signals to a different frequency from the original frequency, the master unit configured to frequency convert the first MIMO channel signal to a frequency that is different from the frequency of the second MIMO channel signal.

3. The distributed antenna system of claim 2 wherein the extension unit is configured to frequency convert all of the MIMO channel signals from the different frequency back to the original frequency for transmission over one or more antennas.

4. The distributed antenna system of claim 1 wherein the master unit generates an LO signal and is configured for transmitting the LO signal to the remote unit over the optical link, the LO signal being used by the master unit for frequency converting at least one of the first and second MIMO channel signals to a different frequency from the original frequency.

5. The distributed antenna system of claim 4 wherein the extension unit is configured to receive the LO signal from the remote unit and use the LO signal for frequency converting at least one of the first and second MIMO channel signals from the different frequency back to the original frequency.

6. The distributed antenna system of claim 4 wherein the remote unit is configured to use the LO signal for frequency converting at least one of the first and second MIMO channel signals from the different frequency back to the original frequency.

7. The distributed antenna system of claim 4, the master unit including circuitry for using the LO signal for generating other frequency signals for use in converting at least one of the first and second MIMO channel signals to a different frequency from the original frequency.

8. The distributed antenna system of claim 1 wherein the optical link includes at least one of the following:

at least one fiber-optic cable for transceiving both uplink signals and downlink signals between the remote unit and master unit or at least two fiber optic cables with one fiber-optic cable for transceiving uplink signals between the remote unit and master unit and another fiber-optic cable for transceiving downlink signals between the remote unit and master unit.

9. The distributed antenna system of claim 1 wherein the master unit is configured to receive at least one non-MIMO signal from a signal source, the master unit configured to combine the non-MIMO signal and MIMO channel signals and transceive the combined signals with the remote unit.

10. The distributed antenna system of claim 9 wherein the non-MIMO signals have an original frequency in a service frequency band, the master unit being further configured to frequency convert at least one of the first and second MIMO channel signals to a different frequency that is close to the service frequency band of the non-MIMO signals.

11. The distributed antenna system of claim 10 wherein the service frequency band is lower in frequency than the original frequency of the MIMO channel signals, the master unit configured to frequency convert at least one of the first and second MIMO channel signals from the original frequency to a lower different frequency that is close to the service frequency band.

12. The distributed antenna system of claim 10 wherein the service frequency band is higher in frequency than the original frequency of the MIMO channel signals, the master unit configured to frequency convert at least one of the first and second MIMO channel signals from the original frequency to a higher different frequency that is close to the service frequency band.

13. The distributed antenna system of claim 1 wherein the master unit is further configured for receiving at least one additional set of MIMO channel signals at another original frequency different from the original frequency of the at least one set of MIMO signals, the master unit being configured to frequency convert at least one of first and second MIMO channel signals of the additional set of MIMO channel signals to another different frequency from the another original frequency, the master unit configured for combining the sets of MIMO channel signals for transmission to the at least one remote unit.

14. The distributed antenna system of claim 13 further comprising at least one additional extension unit coupled to the at least one remote unit, the at least one additional extension unit being configured to receive at least one of the first and second MIMO channel signals of the additional set of MIMO channel signals and to frequency convert at least one of the first and second MIMO channel signals of the additional set from the another different frequency back to the another original frequency for transmission over one or more antennas.

15. The distributed antenna system of claim 13 wherein the master unit is further configured to frequency convert at least one of the first and second MIMO channel signals of the additional set of MIMO channel signals to another different frequency that is close to the original frequency of the at least one set of MIMO channels signals, the master unit configured for combining the sets of MIMO channel signals for transmission to the at least one remote unit.

16. The distributed antenna system of claim 1 wherein at least one of the first and second MIMO channel signals is maintained at an original frequency, the at least one remote unit being configured for transmitting at least one of the first and second MIMO channel signals at the original frequency over one or more antennas.

17. A distributed antenna system, comprising:

a master unit configured to receive a plurality of sets of multiple input multiple output (MIMO) channel signals, at respective original frequencies, from at least one signal source, each set of MIMO channel signals including at least a first MIMO channel signal and a second MIMO channel signal, the master unit being configured to frequency convert at least one of the first and second MIMO channel signals of each set of MIMO channel signals to a different frequency from the respective original frequency of the set, and combine the first MIMO channel signal with the second MIMO channel signal of the set for transmission;

an optical link operably coupled with the master unit;

at least one remote unit in communication with the master unit via the optical link for transceiving the sets of MIMO channel signals between the remote unit and the master unit, the remote unit including at least one extension port configured to transceive at least one of the MIMO signals; and

a plurality of extension units coupled to the at least one remote unit at the extension port, each extension unit being configured to receive at least one MIMO channel signals from a set of MIMO channel signals and to frequency convert the at least one MIMO channel signal of the respective set of MIMO channel signals from the different frequency back to the respective original frequency for the set of MIMO channel signals for transmission over one or more antennas.

18. The distributed antenna system of claim 17 wherein at least one of the first and second MIMO channel signals of a set of signals is maintained at an original frequency, the at least one remote unit being configured for transmitting the at least one of the first and second MIMO channel signals at the original frequency over one or more antennas.

19. The distributed antenna system of claim 17 wherein at least one of the first and second MIMO channel signals of a set of signals is maintained at an original frequency, the extension unit configured for transmitting both the MIMO channel signal of the set at the original frequency and another MIMO channel signal of the set that converted from the different frequency back to the respective original frequency.

20. The distributed antenna system of claim 17 wherein the master unit is configured to receive at least one non-MIMO signal, having an original frequency in a service frequency band, from a signal source, the master unit configured to frequency convert at least one of the first and second MIMO channel signals of a set of MIMO channel signals to a different frequency that is close to the service frequency band of the non-MIMO signals.