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US 9,431,962 B2Granted
Coefficient estimation for digital IQ calibration
AssigneeNXP B.V.
InventorsRobert Rutten, Lucien Johannes Breems, Jan van Sinderen
Life of this patent
Estimating the term…
Abstract
An RF reception system and method uses IF quadrature mixing, in which there is further mixing and channel filtering in the digital domain, to isolate a frequency of interest. A coefficient estimator is used for generating a phase correction coefficient and an amplitude correction coefficient from filtered in-phase and quadrature desired signals and from filtered in-phase and quadrature image signals.
Claims14
An RF receiver, comprising:
- a quadrature mixer which receives the RF input signal and which outputs in-phase and quadrature channels;
- analogue to digital converters for the in-phase and quadrature channels;
- an amplitude compensator for adjusting the amplitude of one or both of the channels to correct for amplitude mismatch, based on an amplitude correction coefficient;
- a phase compensator for adjusting the relative phase between the two channels to correct for phase mismatch, based on a phase correction coefficient;
- a first mixer generating in-phase and quadrature desired signals from the amplitude adjusted and phase adjusted channels by mixing with a first frequency, and a first digital channel filter at the output of the first mixer generating a filtered in-phase desired signal and a filtered quadrature desired signal;
- a second mixer generating in-phase and quadrature image signals from the amplitude adjusted and phase adjusted channels by mixing with a second frequency, and a second digital channel filter at the output of the second mixer generating a filtered in-phase image signal and a filtered quadrature image signal;
- a coefficient estimator for generating the phase correction coefficient and the amplitude correction coefficient from the filtered in-phase and quadrature desired signals and the filtered in-phase and quadrature image signals.
4 more elements
A method for RF reception in an RF receiver, comprising:
- a set of circuits within the RF receiver configured to,
- perform quadrature mixing of a received RF input signal to generate in-phase and quadrature channels;
- convert the in-phase and quadrature channels to digital;
- adjust the amplitude of one or both of the channels to correct for amplitude mismatch, based on an amplitude correction coefficient;
- adjust the relative phase between the two channels to correct for phase mismatch, based on a phase correction coefficient;
- mix and channel filter the amplitude and phase adjusted channels to generate in-phase and quadrature desired signals, by mixing with a first frequency;
- mix and channel filter the amplitude and phase adjusted channels to generate in-phase and quadrature image signals, by mixing with a second frequency;
- and
- generate the phase correction coefficient and the amplitude correction coefficient from the filtered in-phase and quadrature desired signals and the filtered in-phase and quadrature image signals.
6 more elements
Dependencies are inferred from the claim text.