Distributed antenna system for MIMO technologies
First Claim
1. A distributed antenna system for distributing multiple-input, multiple-output (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 radio-frequency (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.
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Accused Products
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.
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Citations
20 Claims
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1. A distributed antenna system for distributing multiple-input, multiple-output (MIMO) signals for at least one MIMO service in a distributed antenna system (DAS), comprising:
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a radio interface unit configured to; receive a plurality of downlink radio-frequency (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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A distributed antenna system for distributing multiple-input, multiple-output (MIMO) signals for at least one MIMO service in a distributed antenna system (DAS), comprising:
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a radio interface unit configured to; receive a plurality of downlink radio-frequency (RFS 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 wireles sly; 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. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A distributed antenna system for distributing multiple-input, multiple-output (MIMO) signals for at least one MIMO service in a distributed antenna system (DAS), comprising:
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a radio interface unit configured to; receive a plurality of downlink radio-frequency (RFS 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 wireles sly; 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. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification