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US 2010/0167680 A1Published application
Controllable image cancellation in a radio receiver
AssigneeSilicon Laboratories Inc.
InventorsJunsong Li, John Khoury
Life of this patent
Estimating the term…
Abstract
In one embodiment, a receiver includes parallel paths for signal channel processing and image channel processing. The paths may include a mixer to receive an intermediate frequency (IF) signal and to downconvert the IF signal to a channel baseband signal, a filter to generate a filtered channel value, a combiner to combine the channel baseband signal with a filtered channel value from the other path to obtain a channel path output, in addition to one or more controllers to generate a step control signal and update a weighting of the filters based at least in part on the step control signal.
Claims20
An apparatus comprising:
- a signal channel path including:
- a first mixer to receive an intermediate frequency (IF) signal and to downconvert the IF signal to a signal channel baseband signal;
- a signal filter to receive a value of the signal channel baseband signal and to generate a filtered signal channel value;
- a first combiner to combine the signal channel baseband signal with a filtered image channel value to obtain a signal channel path output;
- an image channel path including:
- a second mixer to receive the IF signal and to downconvert the IF signal to an image channel baseband signal;
- an image filter to receive a value of the image channel baseband signal and to generate the filtered image channel value;
- a second combiner to combine the image channel baseband signal with the filtered signal channel value to obtain an image channel path output;
- a first controller to determine a signal strength of the signal channel baseband signal and the image channel baseband signal and to generate a step control signal based at least in part on the signal strengths;
- and
- a second controller to receive the signal channel path output and the image channel path output and to update a weighting of the image filter and the signal filter based on the signal channel path output, the image channel path output and the step control signal.
8 more elements
A method comprising:
- calculating a signal strength of a pre-filtered image channel signal and a pre-filtered desired channel signal obtained in a receiver;
- determining whether the signal strength of the pre-filtered image channel signal is greater than the signal strength of the pre-filtered desired channel signal by at least a threshold level;
- and
- if so, enabling image cancellation processing, otherwise disabling the image cancellation processing.
1 more element
A system comprising:
- an antenna to receive a radio frequency (RF) signal;
- an analog front end to receive the RF signal from the antenna and to downconvert the RF signal to an intermediate frequency (IF) signal and to convert the IF signal to a digital complex signal;
- a digital front end coupled to the analog front end, the digital front end including an image canceller to perform image rejection, the image canceller including:
- an image channel path, the image channel path parallel to a signal channel path and including:
- a mixer to receive the digital complex signal, and to downconvert the digital complex signal to an image channel baseband signal;
- an image filter to receive a value of the image channel baseband signal and to generate a filtered image channel value;
- a combiner to combine the image channel baseband signal with a filtered signal channel value from the signal channel path to obtain an image channel path output;
- a first controller to determine a signal strength of a signal channel baseband signal and the image channel baseband signal and to generate a step control signal based at least in part on the signal strengths;
- and
- a second controller to receive a signal channel path output and the image channel path output and to update a weighting of the image filter based on the signal channel path output, the image channel path output and the step control signal;
- and
- a digital signal processor coupled to the digital front end to receive and demodulate the signal channel path output.
9 more elements
Dependencies are inferred from the claim text.