DISTRIBUTED ANTENNA SYSTEM FOR MIMO TECHNOLOGIES

• US 20140211875A1
• Filed: 03/27/2014
• Published: 07/31/2014
• Est. Priority Date: 12/19/2006
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications Wireless Ltd. (Corning Incorporated)
• Inventors: Berlin, Igor, Oren, Yair, Reuven, Rami, Saban, Ofer, Shapira, Isaac
• Granted Patent: US 9,300,372 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 10/271 Combination of different networks, e.g. star and ring configuration in the same network or two ring networks interconnected
• 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 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24

Abstract

The invention is directed to a method and system for supporting MIMO technologies which can require the transport of multiple spatial streams on a traditional Distributed Antenna System (DAS). According to the invention, at one end of the DAS, each spatial stream is shifted in frequency to a pre-assigned band (such as a band at a frequency lower than the native frequency) that does not overlap the band assigned to other spatial streams (or the band of any other services being carried by the DAS). Each of the spatial streams can be combined and transmitted as a combined signal over a common coaxial cable. At the other “end” of the DAS, the different streams are shifted back to their original (overlapping) frequencies but retain their individual “identities” by being radiated through physically separate antenna elements.

Claims

1. A distributed antenna system for distributing MIMO signals for at least one MIMO service in a distributed antenna system (DAS), comprising:

a radio interface unit configured to;

receive a plurality of downlink RF spatial MIMO streams in a native downlink frequency band for at least one MIMO service from at least one base station;

frequency shift at least one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band to at least one non-native, non-overlapping downlink RF spatial MIMO stream; and

combine each of the plurality of downlink RF spatial MIMO streams into a combined downlink RF MIMO signal onto an electrical downlink;

a base unit configured to;

receive the combined downlink RF MIMO signal over the electrical downlink; and

convert the combined downlink RF MIMO signal into a combined downlink optical MIMO signal; and

separate the combined downlink optical MIMO signal into a plurality of combined downlink optical MIMO signals;

a plurality of downlink media converter components each configured to;

receive a combined downlink optical MIMO signal among the plurality of combined downlink optical MIMO signals; and

convert the received combined downlink optical MIMO signal into a combined downlink RF MIMO signal among a plurality of combined downlink RF MIMO signals; and

a plurality of antenna units, each antenna unit among the plurality of antenna units configured to;

separate a combined downlink RF MIMO signal among the plurality of combined downlink RF MIMO signals into separated downlink RF spatial MIMO streams;

frequency shift the at least one non-native, non-overlapping downlink RF spatial MIMO stream from at least one of the separated downlink RF spatial MIMO streams to the native downlink frequency band;

transmit a first downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a first downlink MIMO antenna to be transmitted wirelessly; and

transmit a second downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a second downlink MIMO antenna to be transmitted wirelessly;

the electrical downlink is comprised of a single downlink coaxial cable; and

the radio interface unit further comprising a downlink mixer configured to frequency shift one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band into one non-native, non-overlapping downlink RF spatial MIMO stream, with one downlink RF spatial MIMO stream of the plurality of downlink RF spatial MIMO streams left un-shifted in frequency band from the native downlink frequency band; and

each antenna unit among the plurality of antenna units further configured to convert the one non-native, non-overlapping downlink RF spatial MIMO stream to the native downlink frequency band.

2. The distributed antenna system of claim 1, wherein the downlink mixer is configured to frequency shift the one downlink RF spatial MIMO stream from the native downlink frequency band by being configured to up frequency shift the one downlink RF spatial MIMO stream from the native downlink frequency band into the one non-native, non-overlapping downlink RF spatial MIMO stream comprised of at least one higher frequency, non-native, non-overlapping downlink RF spatial MIMO stream.

3. The distributed antenna system of claim 1, wherein:

the radio interface unit is further configured to;

receive at least one non-MIMO downlink RF signal for at least one non-MIMO service from at least one base station;

frequency shift the at least one non-MIMO downlink RF signal from the native downlink frequency band to at least one non-MIMO non-native, non-overlapping downlink RF signal in frequency band with the plurality of downlink RF spatial MIMO streams; and

combine each of the plurality of downlink RF spatial MIMO streams with the at least one non-MIMO downlink RF signal into the combined downlink RF signal comprising the combined downlink RF MIMO signal and the at least one non-MIMO downlink RF signal onto the electrical downlink; and

wherein each antenna unit among the plurality of antenna units is further configured to;

frequency shift the at least one non-native, non-overlapping downlink RF spatial MIMO stream from the separate downlink RF stream to a downlink RF spatial MIMO stream in the native downlink frequency band, and the at least one non-MIMO downlink RF signal from the separate downlink RF signals to at least one non-MIMO downlink RF signal in the native downlink frequency band; and

transmit the at least one non-MIMO downlink RF signal in the native downlink frequency band to at least one non-MIMO antenna to be transmitted wirelessly.

4. The distributed antenna system of claim 1, wherein:

each antenna unit among the plurality of antenna units is further configured to;

receive a first uplink RF spatial MIMO stream for at least a MIMO service over a first uplink MIMO antenna;

receive a second uplink RF spatial MIMO stream for at least a MIMO service over a second uplink MIMO antenna;

frequency shift at least one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream; and

combine the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream into a combined uplink RF MIMO stream; and

a plurality of uplink media converter components, each uplink media converter among the plurality of uplink media converter components configured to;

receive a combined uplink RF MIMO stream among a plurality of combined uplink RF MIMO streams from an antenna unit among the plurality of antenna units over a respective optical fiber link; and

convert the combined uplink RF MIMO stream into a combined uplink optical MIMO signal among a plurality of combined uplink optical MIMO signals; and

the base unit further configured to;

combine the plurality of combined uplink optical MIMO signals into a combined uplink optical MIMO signal;

convert the combined uplink optical MIMO signal into a combined downlink RF MIMO signal; and

distribute the combined uplink RF MIMO signal over an electrical uplink to the radio interface unit; and

the radio interface unit further configured to;

receive the combined uplink RF MIMO signal over the electrical uplink;

separate the combined uplink RF MIMO signal from the base unit into a plurality of combined first uplink RF spatial MIMO streams and a plurality of combined second uplink RF spatial MIMO streams; and

frequency shift the at least one non-native, non-overlapping uplink RF spatial MIMO stream among the plurality of combined first uplink RF spatial MIMO streams and the plurality of combined second uplink RF spatial MIMO streams into the native uplink frequency band;

wherein the electrical uplink is comprised of a single uplink coaxial cable.

5. The distributed antenna system of claim 4, wherein each antenna unit among the plurality of antenna units is configured to frequency shift one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream.

6. The distributed antenna system of claim 4, wherein each antenna unit among the plurality of antenna units further comprises at least one uplink mixer configured to up frequency shift at least one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream comprised of at least one higher frequency, non-native, non-overlapping uplink RF spatial MIMO stream.

7. The distributed antenna system of claim 4, wherein the first downlink MIMO antenna and the first uplink MIMO antenna are provided in same first MIMO antenna, and the second downlink MIMO antenna and the second uplink MIMO antenna are provided in same second MIMO antenna.

8. A distributed antenna system for distributing MIMO signals for at least one MIMO service in a distributed antenna system (DAS), comprising:

a radio interface unit configured to;

receive a plurality of downlink RF spatial MIMO streams in a native downlink frequency band for at least one MIMO service from at least one base station;

frequency shift at least one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band to at least one non-native, non-overlapping downlink RF spatial MIMO stream; and

combine each of the plurality of downlink RF spatial MIMO streams into a combined downlink RF MIMO signal onto an electrical downlink;

a base unit configured to;

receive the combined downlink RF MIMO signal over the electrical downlink; and

convert the combined downlink RF MIMO signal into a combined downlink optical MIMO signal; and

separate the combined downlink optical MIMO signal into a plurality of combined downlink optical MIMO signals;

a plurality of downlink media converter components each configured to;

receive a combined downlink optical MIMO signal among the plurality of combined downlink optical MIMO signals; and

convert the received combined downlink optical MIMO signal into a combined downlink RF MIMO signal among a plurality of combined downlink RF MIMO signals; and

a plurality of antenna units, each antenna unit among the plurality of antenna units configured to;

separate a combined downlink RF MIMO signal among the plurality of combined downlink RF MIMO signals into separated downlink RF spatial MIMO streams;

frequency shift the at least one non-native, non-overlapping downlink RF spatial MIMO stream from at least one of the separated downlink RF spatial MIMO streams to the native downlink frequency band;

transmit a first downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a first downlink MIMO antenna to be transmitted wirelessly; and

transmit a second downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a second downlink MIMO antenna to be transmitted wirelessly;

the electrical downlink is comprised of a single downlink coaxial cable; and

the radio interface unit configured to frequency shift the at least one of the plurality of downlink RF spatial MIMO streams by being configured to up frequency shift the at least one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band to the at least one non-native, non-overlapping downlink RF spatial MIMO stream comprised of at least one higher frequency, non-native, non-overlapping downlink RF spatial MIMO stream.

9. The distributed antenna system of claim 8, wherein:

each antenna unit among the plurality of antenna units is further configured to;

receive a first uplink RF spatial MIMO stream for at least a MIMO service over a first uplink MIMO antenna;

receive a second uplink RF spatial MIMO stream for at least a MIMO service over a second uplink MIMO antenna;

frequency shift at least one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream; and

combine the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream into a combined uplink RF MIMO stream; and

a plurality of uplink media converter components each configured to;

receive a combined uplink RF MIMO stream among a plurality of combined uplink RF MIMO streams from an antenna unit among the plurality of antenna units over a respective optical fiber link; and

convert the combined uplink RF MIMO stream into a combined uplink optical MIMO signal among a plurality of combined uplink optical MIMO signals; and

the base unit further configured to;

combine the plurality of combined uplink optical MIMO signals into a combined uplink optical MIMO signal;

convert the combined uplink optical MIMO signal into a combined downlink RF MIMO signal; and

distribute the combined uplink RF MIMO signal over an electrical uplink to the radio interface unit; and

the radio interface unit further configured to;

receive the combined uplink RF MIMO signal over the electrical uplink;

separate the combined uplink RF MIMO signal from the base unit into a plurality of combined first uplink RF spatial MIMO streams and a plurality of combined second uplink RF spatial MIMO streams; and

frequency shift the at least one non-native, non-overlapping uplink RF spatial MIMO stream among the plurality of combined first uplink RF spatial MIMO streams and the plurality of combined second uplink RF spatial MIMO streams into the native uplink frequency band;

wherein each antenna unit among the plurality of antenna units further comprises at least one uplink mixer configured to up frequency shift at least one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream comprised of at least one higher frequency, non-native, non-overlapping uplink RF spatial MIMO stream.

10. The distributed antenna system of claim 9, wherein the electrical uplink is comprised of a single uplink coaxial cable.

11. The distributed antenna system of claim 9, wherein each antenna unit among the plurality of antenna units is configured to frequency shift one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream.

12. The distributed antenna system of claim 9, wherein the first downlink MIMO antenna and the first uplink MIMO antenna are provided in same first MIMO antenna, and the second downlink MIMO antenna and the second uplink MIMO antenna are provided in same second MIMO antenna.

13. The distributed antenna system of claim 9, wherein:

the base unit further comprises;

a plurality of wave division multiplexers each configured to;

receive a combined downlink optical MIMO signal among the plurality of combined downlink optical MIMO signals;

wave division multiplex the received combined downlink optical MIMO signal onto the respective optical fiber link;

receive the combined uplink optical MIMO signal from an antenna unit among the plurality of antenna units over the respective optical fiber link; and

wave division demultiplex the received combined uplink optical MIMO signal from the respective optical fiber link; and

each antenna unit among the plurality of antenna units further comprises;

a wave division multiplexer configured to;

receive the combined uplink optical MIMO signal; and

wave division multiplex the received combined uplink optical MIMO signal onto the respective optical fiber link;

receive the combined downlink optical MIMO signal among the plurality of combined downlink optical MIMO signals from the respective optical fiber link; and

wave division demultiplex the received combined downlink optical MIMO signal from the respective optical fiber link.

14. A distributed antenna system for distributing MIMO signals for at least one MIMO service in a distributed antenna system (DAS), comprising:

a radio interface unit configured to;

receive a plurality of downlink RF spatial MIMO streams in a native downlink frequency band for at least one MIMO service from at least one base station;

frequency shift at least one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band to at least one non-native, non-overlapping downlink RF spatial MIMO stream; and

combine each of the plurality of downlink RF spatial MIMO streams into a combined downlink RF MIMO signal onto an electrical downlink;

a base unit configured to;

receive the combined downlink RF MIMO signal over the electrical downlink; and

convert the combined downlink RF MIMO signal into a combined downlink optical MIMO signal; and

separate the combined downlink optical MIMO signal into a plurality of combined downlink optical MIMO signals;

a plurality of downlink media converter components each configured to;

receive a combined downlink optical MIMO signal among the plurality of combined downlink optical MIMO signals; and

convert the received combined downlink optical MIMO signal into a combined downlink RF MIMO signal among a plurality of combined downlink RF MIMO signals; and

a plurality of antenna units, each antenna unit among the plurality of antenna units configured to;

separate a combined downlink RF MIMO signal among the plurality of combined downlink RF MIMO signals into separated downlink RF spatial MIMO streams;

frequency shift the at least one non-native, non-overlapping downlink RF spatial MIMO stream from at least one of the separated downlink RF spatial MIMO streams to the native downlink frequency band;

transmit a first downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a first downlink MIMO antenna to be transmitted wirelessly; and

transmit a second downlink RF MIMO spatial stream among the separated downlink RF spatial MIMO streams in the native downlink frequency band to a second downlink MIMO antenna to be transmitted wirelessly;

the radio interface unit is further configured to;

receive at least one non-MIMO downlink RF signal for at least one non-MIMO service from at least one base station;

frequency shift the at least one non-MIMO downlink RF signal from the native downlink frequency band to at least one non-MIMO non-native, non-overlapping downlink RF signal in frequency band with the plurality of downlink RF spatial MIMO streams; and

combine each of the plurality of downlink RF spatial MIMO streams with the at least one non-MIMO downlink RF signal into the combined downlink RF signal comprising the combined downlink RF MIMO signal and the at least one non-MIMO downlink RF signal onto the electrical downlink; and

wherein each antenna unit among the plurality of antenna units is further configured to;

frequency shift the at least one non-native, non-overlapping downlink RF spatial MIMO stream from the separate downlink RF stream to a downlink RF spatial MIMO stream in the native downlink frequency band, and the at least one non-MIMO downlink RF signal from the separate downlink RF signals to at least one non-MIMO downlink RF signal in the native downlink frequency band; and

transmit the at least one non-MIMO downlink RF signal in the native downlink frequency band to at least one non-MIMO antenna to be transmitted wirelessly.

15. The distributed antenna system of claim 14, wherein the electrical downlink is comprised of a single downlink coaxial cable.

16. The distributed antenna system of claim 14, further comprising:

at least one downlink mixer in the radio interface unit is configured to frequency shift one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band into one non-native, non-overlapping downlink RF spatial MIMO streams, with one downlink spatial MIMO stream of the plurality of downlink RF spatial MIMO streams left un-shifted in frequency band at the native downlink frequency band; and

each antenna unit among the plurality of antenna units configured to convert the one non-native, non-overlapping downlink RF spatial MIMO streams to the native downlink frequency band.

17. The distributed antenna system of claim 14, wherein the radio interface unit is configured to frequency shift the at least one of the plurality of downlink RF spatial MIMO streams by being configured to up frequency shift the at least one of the plurality of downlink RF spatial MIMO streams from the native downlink frequency band to the at least one non-native, non-overlapping downlink RF spatial MIMO stream comprised of at least one higher frequency, non-native, non-overlapping downlink RF spatial MIMO stream.

18. The distributed antenna system of claim 14, wherein:

each antenna unit among the plurality of antenna units is further configured to;

receive a first uplink RF spatial MIMO stream for at least a MIMO service over a first uplink MIMO antenna;

receive a second uplink RF spatial MIMO stream for at least a MIMO service over a second uplink MIMO antenna;

frequency shift at least one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream; and

combine the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream into a combined uplink RF MIMO stream; and

a plurality of uplink media converter components, each uplink media converter among the plurality of uplink media converter components configured to;

receive a combined uplink RF MIMO stream among a plurality of combined uplink RF MIMO streams from an antenna unit among the plurality of antenna units over a respective optical fiber link; and

convert the combined uplink RF MIMO stream into a combined uplink optical MIMO signal among a plurality of combined uplink optical MIMO signals; and

the base unit further configured to;

combine the plurality of combined uplink optical MIMO signals into a combined uplink optical MIMO signal;

convert the combined uplink optical MIMO signal into a combined downlink RF MIMO signal; and

distribute the combined uplink RF MIMO signal over an electrical uplink to the radio interface unit; and

the radio interface unit further configured to;

receive the combined uplink RF MIMO signal over the electrical uplink;

separate the combined uplink RF MIMO signal from the base unit into a plurality of combined first uplink RF spatial MIMO streams and a plurality of combined second uplink RF spatial MIMO streams; and

frequency shift the at least one non-native, non-overlapping uplink RF spatial MIMO stream among the plurality of combined first uplink RF spatial MIMO streams and the plurality of combined second uplink RF spatial MIMO streams into the native uplink frequency band;

19. The distributed antenna system of claim 18, wherein the electrical uplink is comprised of a single uplink coaxial cable.

20. The distributed antenna system of claim 18, wherein each antenna unit among the plurality of antenna units is configured to frequency shift one of the first uplink RF spatial MIMO stream and the second uplink RF spatial MIMO stream from a native uplink frequency band to at least one non-native, non-overlapping uplink RF spatial MIMO stream.