US 9,807,700 B2Granted

Offsetting unwanted downlink interference signals in an uplink path in a distributed antenna system (DAS)

AssigneeCorning Optical Communications Wireless Ltd

InventorDror Harel

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Abstract

Offsetting unwanted downlink interference signals in an uplink path in a distributed antenna system (DAS) is disclosed. In this regard, in one example, an interference signal offset circuit is provided in an RAU to offset interference products leaked from a downlink path to an uplink path. An offset signal generation circuit is configured to generate at least one uplink interference offset signal based on the interference products leaked from the downlink path. A signal summing circuit is configured to combine the at least one uplink interference offset signal with an uplink signal received on the uplink path, thus offsetting the interference products in the uplink signal. By providing the interference signal offset circuit in the RAU to offset the interference products on the uplink path, it is possible to provide more implementation flexibility for the RAU without degrading the uplink signal.

Claims29

Dependent claims

An interference signal offset circuit in a distributed antenna system (DAS), comprising:

at least one offset signal generation circuit configured to:
receive a downlink signal in a downlink path, the downlink signal comprising one or more downlink communications signals and at least one unwanted downlink interference signal resulting from the one or more downlink communications signals;
and
generate at least one uplink interference offset signal based on the received at least one unwanted downlink interference signal;
a signal summing circuit configured to:
receive an uplink signal in an uplink path, the uplink signal comprising a wanted uplink signal and the at least one unwanted downlink interference signal leaked from the downlink path to the uplink path;
receive the at least one uplink interference offset signal;
generate an output uplink signal based on the received uplink signal;
and
combine the received at least one uplink interference offset signal with the received uplink signal to offset the at least one unwanted downlink interference signal from the output uplink signal;
and
a control circuit configured to:
receive the output uplink signal from the signal summing circuit;
and
configure the at least one offset signal generation circuit to generate the at least one uplink interference offset signal to offset the at least one unwanted downlink interference signal;
the interference signal offset circuit configured to operate in a test mode, wherein the control circuit is further configured to:
decouple at least one antenna from a coupling device communicatively coupled to the at least one antenna;
decouple the at least one offset signal generation circuit from the signal summing circuit;
receive a downlink test signal in the downlink path, wherein the downlink test signal comprises one or more downlink test interference products;
receive an uplink test signal in the uplink path, wherein the uplink test signal comprises the one or more downlink test interference products leaked from the downlink path to the uplink path;
and
measure a power level of at least one downlink test interference product among the one or more downlink test interference products.

19 more elements

A method of offsetting at least one unwanted downlink interference signal from an uplink signal received in a distributed antenna system (DAS), comprising:

decoupling at least one antenna from a coupling device communicatively coupled to the at least one antenna;
decoupling at least one offset signal generation circuit from a signal summing circuit;
receiving a downlink test signal in a downlink path, wherein the downlink test signal comprises one or more downlink test interference products;
receiving an uplink test signal in an uplink path, wherein the uplink test signal comprises the one or more downlink test interference products leaked from the downlink path to the uplink path;
measuring a power level of at least one downlink test interference product among the one or more downlink test interference products;
receiving a downlink signal in the downlink path, wherein the downlink signal comprises one or more downlink communications signals and at least one unwanted downlink interference signal resulting from the one or more downlink communications signals;
generating at least one uplink interference offset signal based on the received at least one unwanted downlink interference signal;
receiving an uplink signal in the uplink path from the coupling device communicatively coupled to the at least one antenna, wherein the coupling device is further configured to provide the downlink signal to the at least one antenna, wherein the uplink signal comprises a wanted uplink signal and the at least one unwanted downlink interference signal leaked from the downlink path to the uplink path;
generating an output uplink signal based on the uplink signal;
and
combining the at least one uplink interference offset signal with the uplink signal to offset the at least one unwanted downlink interference signal in the output uplink signal.

8 more elements

A remote antenna unit (RAU) in a distributed antenna system (DAS), comprising:

a downlink power amplifier configured to amplify one or more downlink communications signals received in a downlink path to generate a downlink signal in the downlink path, the downlink signal comprising at least one unwanted downlink interference signal resulting from the one or more downlink communications signals;
at least one antenna configured to transmit the downlink signal and receive an uplink signal;
a coupling device communicatively coupled to the downlink power amplifier and the at least one antenna, wherein the coupling device is configured to:
distribute the downlink signal received from the downlink path to the at least one antenna for transmission;
and
distribute the uplink signal received from the at least one antenna to an uplink path, the uplink signal comprising a wanted uplink signal and the at least one unwanted downlink interference signal leaked from the downlink path to the uplink path;
a first switch configured to couple the coupling device to the at least one antenna or decouple the coupling device from the at least one antenna;
and
an interference signal offset circuit, comprising:
at least one offset signal generation circuit configured to:
receive the downlink signal comprising the one or more downlink communications signals and the at least one unwanted downlink interference signal;
and
generate at least one uplink interference offset signal based on the received at least one unwanted downlink interference signal;
a signal summing circuit, comprising:
a second switch configured to couple or decouple the signal summing circuit with the coupling device;
a third switch configured to couple or decouple the signal summing circuit with the at least one offset signal generation circuit;
a signal summing point coupled to the second switch and the third switch, wherein the signal summing point is configured to combine the at least one uplink interference offset signal with the uplink signal to offset the at least one unwanted downlink interference signal from an output uplink signal;
and
an uplink low noise amplifier (LNA) coupled to the signal summing point;
wherein the signal summing circuit is configured to:
receive the uplink signal in the uplink path;
receive the at least one uplink interference offset signal;
generate the output uplink signal based on the received uplink signal;
and
combine the received at least one uplink interference offset signal with the received uplink signal to offset the at least one unwanted downlink interference signal from the output uplink signal;
and
a control circuit configured to:
receive the output uplink signal from the signal summing circuit;
and
configure the at least one offset signal generation circuit to generate the at least one uplink interference offset signal to offset the at least one unwanted downlink interference signal.

27 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/042,532Filed 12 Feb 2016 · us provisional application
Priority: 19 Feb 2015
Published: US 2016/0249346 A125 Aug 2016
Granted: 31 Oct 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H04W 52/243
Using SIR [Signal to Interference Ratio] or other wireless path parameters: taking into account interferences
H04B 17/11
Of transmitters: for calibration
H04B 17/345
Measuring or estimating channel quality parameters: interference values
H04W 72/20
Local resource management: control channels or signalling for resource management