Estimation and reduction of second order distortion in real time
AssigneeResearch In Motion Limited
InventorTajinder MANKU
Life of this patent
Estimating the term…
Abstract
A radio receiver method of reducing second order distortion components involves at a first mixer, mixing an input signal with an oscillator signal to generate an I component of a received radio communication signal; at a second mixer, mixing the input signal with a phase shifted oscillator signal to generate a Q component of the received radio communication signal; computing an estimate of second order distortion as a function of the I and Q components of the received radio communication signal; and adjusting an operational parameter of the radio receiver to reduce the estimated value of second order distortion components. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.
Claims20
In a radio receiver, a method of reducing second order distortion components, comprising:
- at a first mixer, mixing an input signal with an oscillator signal to generate an I component of a received radio communication signal;
- at a second mixer, mixing the input signal with a phase shifted oscillator signal to generate a Q component of the received radio communication signal;
- computing an estimate of second order distortion as a function of the I and Q components of the received radio communication signal;
- and
- adjusting an operational parameter of the radio receiver to reduce the estimated value of second order distortion components.
A radio receiver, comprising:
- a local oscillator;
- a first mixer, configured to mix an input signal with a local oscillator signal from the local oscillator to generate an I component of a received radio communication signal;
- a second mixer, configured to mix the input signal with a phase shifted local oscillator signal to generate a Q component of the received radio communication signal;
- a processor programmed to:
- compute an estimate of second order distortion as a function of the I and Q components of the received radio communication signal;
- and
- adjust an operational parameter of the radio receiver to reduce the estimate of second order distortion components.
A radio receiver, comprising:
- a local oscillator;
- a first mixer, configured to mix an input signal with a local oscillator signal from the local oscillator to generate an I component of a received radio communication signal;
- a second mixer, configured to mix the input signal with a phase shifted local oscillator signal to generate a Q component of the received radio communication signal;
- a programmed processor;
- one or more digital to analog converters coupled to the processor and configured to convert digital control signals from the processor a voltage that sets a bias level of one or both of the first and second mixers;
- where the processor is programmed to:
- compute an estimate of second order distortion as a function of the I and Q components of the received radio communication signal as either <I2>−<Q2> or <IQ>;
- and
- adjust an operational parameter of the radio receiver to reduce the estimate of second order distortion components.
Dependencies are inferred from the claim text.