Systems, methods, and devices for improving signal quality
AssigneeMotorola Solutions, Inc.
InventorsDavid P. Gurney, Stephen L. Kuffner
Life of this patent
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Abstract
Improving signal quality by sampling an intermediate frequency signal by an analog-to-digital converter (ADC) and determining spectral characteristic data of the output signal of the ADC, and processing the spectral characteristic data to identify blocking signals and blocking spur signals that interfere with any desired signals. An adjustment is made to the frequency of one or more oscillators to reduce the interference resulting from the blocking signals if a ratio of the desired signal level to the total interfering blocker spur level is below a threshold.
Claims20
A method for improving signal quality in a receiver, comprising:
- receiving a signal having a bandwidth containing at least a desired channel signal, at a desired channel frequency, using a local oscillator of the receiver;
- sampling the received signal using an analog-to-digital converter (ADC) in the receiver to provide a digitized output signal of the ADC;
- determining spectral characteristic data relating to the digitized output signal of the ADC;
- processing the spectral characteristic data to identify one or more blocking signals and corresponding blocking signal frequencies;
- determining one or more blocking spur signals, each having a blocking spur level and corresponding blocking spur frequency based on the one or more blocking signals and ADC characterization data;
- calculating a ratio of an estimated desired channel signal level to a total interfering blocking spur level, wherein the total interfering blocking spur level is the sum of each blocking spur level that falls into the desired channel;
- determining whether the ratio is below a first threshold;
- and
- adjusting the frequency of one or more oscillators in the receiver based on the ratio being below the first threshold.
An apparatus comprising:
- an intermediate frequency (IF) mixer connected to an IF oscillator generating an IF signal having a bandwidth containing a plurality of channels, including a desired channel signal at a desired channel frequency;
- an analog-to-digital converter (ADC) coupled to the IF-mixer wherein an input signal of the ADC is the IF signal and an output signal of the ADC is a sampled IF signal;
- a frequency analysis module, coupled to the ADC, configured to determine spectral characteristic data of the sampled IF signal;
- an interference assessment module configured to:
- process the spectral characteristic data to identify one or more blocking signals and their corresponding harmonic blocking signal frequencies;
- determine one or more harmonic blocking spur signals, each having a blocking spur level and corresponding blocking spur frequency based on the one or more harmonic blocking signals and ADC characterization data;
- calculate a ratio of a desired channel signal level to a total interfering spur level wherein each interfering spur signal has an interfering spur level and the total interfering spur level is the sum of each interfering spur level;
- determine whether the ratio is below a first threshold;
- and
- provide instructions to adjust the frequency of one or more oscillators based on the ratio being below the first threshold.
Dependencies are inferred from the claim text.