Self-interference cancellation
AssigneeBroadcom Corporation
InventorsNihar Jindal, Jun Shi, Sriram Sundararajan, Arya Behzad, Marcellus Forbes, Ling Su
Life of this patent
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Abstract
A communication device, such as a smart phone, includes transmit/receive logic to cancel an interfering signal component. The interfering signal component may originate from a communication interface on the device itself. For example, transmissions from the communication interface may interfere with received signals at other communication interfaces on the device. Transmit/receive logic on others of the communication interfaces may use known characteristics of the interfering signal component to cancel the interfering signal component.
Claims20
A system comprising:
- a first wireless interface configured to transmit a data stream over a wireless channel;
- a second wireless interface configured to receive an input signal including a signal component arising from transmission of the data stream;
- a reference path configured to provide a reference signal from the first wireless interface to the second wireless interface;
- a cancellation filter configured to attempt to match the reference signal to the signal component, and provide a cancellation output;
- removal circuitry configured to remove the cancellation output from the input signal received at the second wireless interface;
- and
- control circuitry configured to:
- request a training period to train the cancellation filter;
- and
- train the cancellation filter to match an effect of the wireless channel by:
- performing a cancellation analysis of the signal component during the training period;
- and
- setting a parameter of the cancellation filter responsive to the cancellation analysis.
A method comprising:
- transmitting a first signal from a first antenna;
- receiving an interference component arising from the first signal on a second antenna;
- receiving a reference via a reference path;
- transmitting an impending transmission indicator to request a training period from network controller circuitry;
- and
- training a cancellation filter in the reference path based on the interference component and reference signal, during the training period.
A device comprising;
- a first wireless interface configured to transmit a first signal associated with a first protocol;
- a second wireless interface configured to:
- receive a second signal associated with a second protocol from network controller circuitry, the second protocol being different from the first protocol;
- receive a self-interfering signal component arising from the first signal;
- and
- convert the second signal and self-interfering signal component to a digital stream with a digital self-interfering component;
- and
- a reference path comprising:
- a digital signal source configured to provide a digital reference signal having a common origin with the first signal;
- a cancellation filter to attempt configured to match the reference signal to the digital self-interfering component to produce a cancellation output;
- and
- removal circuitry coincident with the second wireless interface, the removal circuitry configured to destructively combine the cancellation output and digital self-interfering component.
Dependencies are inferred from the claim text.