REDUCING LOCATION-DEPENDENT INTERFERENCE IN DISTRIBUTED ANTENNA SYSTEMS OPERATING IN MULTIPLE-INPUT, MULTIPLE-OUTPUT (MIMO) CONFIGURATION, AND RELATED COMPONENTS, SYSTEMS, AND METHODS

摘要

Components, systems, and methods for reducing location-based 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 spatial (i.e., phase) separation in the received MIMO communications signals. Thus, to provide phase separation of received MIMO communication 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 phase shifted in one of the polarization states to provide phase separation between received MIMO communication signals. In other embodiments, multiple transmitter antennas in a MIMO transmitter can be offset to provide phase separation.

主权项

1. A 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; and 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 in a first phase 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; andreceive a second downlink MIMO communications signal in the first phase 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 in the first phase 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; andreceive a fourth downlink MIMO communications signal over a fourth downlink communications medium, and transmit the fourth downlink MIMO communications signal in a second phase shifted from the first phase, wirelessly as a fourth electrical downlink MIMO communications signal over the fourth MIMO transmitter antenna in the second polarization.