Reducing location-dependent destructive interference in distributed antenna systems (DASS) operating in multiple-input, multiple-output (MIMO) configuration, and related components, systems, and methods
First Claim
1. A multiple-input, multiple-output (MIMO) remote unit configured to wirelessly distribute MIMO communications signals to wireless client devices in a distributed antenna system, comprising:
- a first MIMO transmitter comprising;
a first MIMO transmitter antenna configured to transmit MIMO communications signals in a first polarization and a second MIMO transmitter antenna configured to transmit MIMO communications signals in a second polarization different from the first polarization;
a second MIMO transmitter comprising a third MIMO transmitter antenna configured to transmit MIMO communications signals in the first polarization and a fourth MIMO transmitter antenna configured to transmit MIMO communications signals in the second polarization;
the first MIMO transmitter configured to;
receive a first downlink MIMO communications signal at a first amplitude over a first downlink communications medium, and transmit the first downlink MIMO communications signal wirelessly as a first electrical downlink MIMO communications signal over the first MIMO transmitter antenna in the first polarization; and
receive a second downlink MIMO communications signal at the first amplitude over a second downlink communications medium, and transmit the second downlink MIMO communications signal wirelessly as a second electrical downlink MIMO communications signal over the second MIMO transmitter antenna in the second polarization;
the second MIMO transmitter configured to;
receive a third downlink MIMO communications signal at the first amplitude over a third downlink communications medium, and transmit the third downlink MIMO communications signal wirelessly as a third electrical downlink MIMO communications signal over the third MIMO transmitter antenna in the first polarization; and
receive a fourth downlink MIMO communications signal over a fourth downlink communications medium, and transmit the fourth downlink MIMO communications signal at a second amplitude modified from the first amplitude, wirelessly as a fourth electrical downlink MIMO communications signal over the fourth MIMO transmitter antenna in the second polarization.
1 Assignment
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Accused Products
Abstract
Components, systems, and methods for reducing location-dependent destructive interference in distributed antenna systems operating in multiple-input, multiple-output (MIMO) configuration are disclosed. Interference is defined as issues with received MIMO communications signals that can cause a MIMO algorithm to not be able to solve a channel matrix for MIMO communications signals received by MIMO receivers in client devices. These issues may be caused by lack of separation (i.e., phase, amplitude) in the received MIMO communications signals. Thus, to provide amplitude separation of received MIMO communications signals, multiple MIMO transmitters are each configured to employ multiple transmitter antennas, which are each configured to transmit in different polarization states. In certain embodiments, one of the MIMO communications signals is amplitude adjusted in one of the polarization states to provide amplitude separation between received MIMO communications signals. In other embodiments, multiple transmitter antennas in a MIMO transmitter can be offset to provide amplitude separation.
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Citations
22 Claims
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1. A multiple-input, multiple-output (MIMO) remote unit configured to wirelessly distribute MIMO communications signals to wireless client devices in a distributed antenna system, comprising:
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a first MIMO transmitter comprising;
a first MIMO transmitter antenna configured to transmit MIMO communications signals in a first polarization and a second MIMO transmitter antenna configured to transmit MIMO communications signals in a second polarization different from the first polarization;a second MIMO transmitter comprising a third MIMO transmitter antenna configured to transmit MIMO communications signals in the first polarization and a fourth MIMO transmitter antenna configured to transmit MIMO communications signals in the second polarization; the first MIMO transmitter configured to; receive a first downlink MIMO communications signal at a first amplitude over a first downlink communications medium, and transmit the first downlink MIMO communications signal wirelessly as a first electrical downlink MIMO communications signal over the first MIMO transmitter antenna in the first polarization; and receive a second downlink MIMO communications signal at the first amplitude over a second downlink communications medium, and transmit the second downlink MIMO communications signal wirelessly as a second electrical downlink MIMO communications signal over the second MIMO transmitter antenna in the second polarization; the second MIMO transmitter configured to; receive a third downlink MIMO communications signal at the first amplitude over a third downlink communications medium, and transmit the third downlink MIMO communications signal wirelessly as a third electrical downlink MIMO communications signal over the third MIMO transmitter antenna in the first polarization; and receive a fourth downlink MIMO communications signal over a fourth downlink communications medium, and transmit the fourth downlink MIMO communications signal at a second amplitude modified from the first amplitude, wirelessly as a fourth electrical downlink MIMO communications signal over the fourth MIMO transmitter antenna in the second polarization. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of transmitting multiple-input, multiple-output (MIMO) communications signals to wireless client devices in a distributed antenna system, comprising:
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receiving a first downlink MIMO communications signal at a first amplitude over a first downlink communications medium; transmitting the first downlink MIMO communications signal wirelessly as a first electrical downlink MIMO communications signal over a first MIMO transmitter antenna in a first polarization; and receiving a second downlink MIMO communications signal at the first amplitude over a second downlink communications medium; transmitting the second downlink MIMO communications signal wirelessly as a second electrical downlink MIMO communications signal over a second MIMO transmitter antenna in a second polarization; receiving a third downlink MIMO communications signal at the first amplitude over a third downlink communications medium; transmitting the third downlink MIMO communications signal wirelessly as a third electrical downlink MIMO communications signal over a third MIMO transmitter antenna in the first polarization; receiving a fourth downlink MIMO communications signal over a fourth downlink communications medium; and transmitting the fourth downlink MIMO communications signal at a second amplitude modified from the first amplitude, wirelessly as a fourth electrical downlink MIMO communications signal over a fourth MIMO transmitter antenna in the second polarization. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A distributed antenna system for distributing multiple-input, multiple-output (MIMO) communications signals to wireless client devices, comprising:
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a central unit comprising a central unit transmitter configured to receive a downlink communications signal, and transmit the received downlink communications signal as a first downlink MIMO communications signal over a first downlink communications medium, a second downlink MIMO communications signal over a second downlink communications medium, a third downlink MIMO communications signal over a third downlink communications medium, and a fourth downlink MIMO communications signal over a fourth downlink communications medium; and a remote unit, comprising; a first MIMO transmitter comprising a first MIMO transmitter antenna configured to transmit MIMO communications signals in a first polarization and a second MIMO transmitter antenna configured to transmit MIMO communications signals in a second polarization different from the first polarization; a second MIMO transmitter comprising a third MIMO transmitter antenna configured to transmit MIMO communications signals in the first polarization and a fourth MIMO transmitter antenna configured to transmit MIMO communications signals in the second polarization; the first MIMO transmitter configured to; receive a first downlink MIMO communications signal at a first amplitude over a first downlink communications medium, and transmit the first downlink MIMO communications signal wirelessly as a first electrical downlink MIMO communications signal over the first MIMO transmitter antenna in the first polarization; and receive a second downlink MIMO communications signal at the first amplitude over a second downlink communications medium, and transmit the second downlink MIMO communications signal wirelessly as a second electrical downlink MIMO communications signal over the second MIMO transmitter antenna in the second polarization; the second MIMO transmitter configured to; receive a third downlink MIMO communications signal at the first amplitude over a third downlink communications medium, and transmit the third downlink MIMO communications signal wirelessly as a third electrical downlink MIMO communications signal over the third MIMO transmitter antenna in the first polarization; and receive a fourth downlink MIMO communications signal over a fourth downlink communications medium, and transmit the fourth downlink MIMO communications signal at a second amplitude modified from the first amplitude, wirelessly as a fourth electrical downlink MIMO communications signal over the fourth MIMO transmitter antenna in the second polarization; and at least one amplitude adjustment circuit configured to amplitude adjust the fourth downlink MIMO communications signal to the second amplitude. - View Dependent Claims (21, 22)
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Specification