Dynamic selection of local oscillator signal injection for image rejection in integrated receivers
First Claim
Patent Images
1. A method for dynamically selecting high-side or low-side injection of local oscillator mixing signals to help reject images within a receiver, comprising:
- providing a mixer configured to utilize a mixing signal to mix an input signal to a desired frequency;
receiving an RF signal spectrum including a plurality of channels;
identifying a channel within the RF signal spectrum to be tuned;
assessing signal power at one or more frequencies within the RF signal spectrum that are different from the frequency of the channel to be tuned;
selecting high-side injection or low-side injection for the mixing signal based upon the signal power assessment;
generating a high-side local oscillation (LO) signal if high-side injection is selected, and generating a low-side local oscillation (LO) signal if low-side injection is selected; and
mixing the RF signal spectrum with the local oscillation signal that was selected and generated so as to mix the channel to be tuned down to the desired frequency.
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Abstract
A system and method are disclosed for dynamically selecting high-side injection or low-side injection of local oscillator mixing signals based upon an assessment of signal power within the input signal spectrum that could cause unwanted images in the processed signal. This image rejection assessment provides an advantageous basis upon which to make dynamic high-side versus low-side injection determinations.
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Citations
22 Claims
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1. A method for dynamically selecting high-side or low-side injection of local oscillator mixing signals to help reject images within a receiver, comprising:
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providing a mixer configured to utilize a mixing signal to mix an input signal to a desired frequency; receiving an RF signal spectrum including a plurality of channels; identifying a channel within the RF signal spectrum to be tuned; assessing signal power at one or more frequencies within the RF signal spectrum that are different from the frequency of the channel to be tuned; selecting high-side injection or low-side injection for the mixing signal based upon the signal power assessment; generating a high-side local oscillation (LO) signal if high-side injection is selected, and generating a low-side local oscillation (LO) signal if low-side injection is selected; and mixing the RF signal spectrum with the local oscillation signal that was selected and generated so as to mix the channel to be tuned down to the desired frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An integrated receiver, comprising:
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a mixer coupled to receive an RF signal spectrum and a mixing signal as inputs and having a mixed signal as an output, the RF signal spectrum comprising a plurality of channels; local oscillator (LO) generation circuitry configured to provide an oscillation signal as an output, the oscillation signal being used to generate the mixing signal for the mixer; conversion circuitry coupled to receive the mixed signal from the mixer and configured to output a digital signal; digital-signal-processor (DSP) circuitry coupled to receive the digital signal from the conversion circuitry and configured to output a tuned digital signal, the DSP circuitry including signal power determination circuitry; and control circuitry coupled to the DSP and to the LO generation circuitry, the control circuitry being configured to receive signals from the signal power determination circuitry, to receive a channel selection signal, to select high-side or low-side injection based upon a signal power assessment of one or more frequencies within the RF signal spectrum, and to control the LO generation circuitry to provide a high-side LO signal or a low-side LO signal depending upon the injection selection. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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Specification