Radio Receiver Signal Processor for Motor Interference Reduction

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Solution Overview

Problem

Vehicle radio receivers in car infotainment systems suffer from degraded analog and digital radio reception quality due to electrical motor interference, particularly affecting AM radio, and existing methods fail to effectively suppress interference without impairing the detection of desired signals.

Innovation Solution

A signal processor that estimates the frequency domain spectral repetition interval of interference signals from electric motors driven by inverters and generates an interference reference signal to subtract from the input signal, utilizing frequency estimation and synthesis techniques to improve signal-to-noise ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional radio reception methods are used in vehicle infotainment systems, then the system structure remains simple, but the radio reception quality is degraded due to electrical motor interference

Engineering Contradiction:
Improveradio reception qualityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an interference reference signal as an intermediary element that represents the motor interference characteristics. This reference signal is generated by estimating the spectral repetition interval of the interference and synthesizing a signal with matching properties. The interference reference signal then serves as a mediator that, when subtracted from the received signal, removes the interference without affecting the desired radio content, thus improving reception quality while maintaining manageable system complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of the interference signal by estimating its spectral repetition interval and synthesizing an interference reference signal that replicates the interference characteristics. This synthetic copy is then subtracted from the original received signal to eliminate the interference. The copying approach allows selective removal of interference patterns without needing to directly process or identify each interference instance in real-time

Inventive Principle:
Principle #26Copying

2Object-affected harmful factors

If existing interference suppression methods are applied, then some interference reduction is achieved, but the detection of desired signals is impaired

Engineering Contradiction:
Improveinterference reductionVSAvoidsignal detection accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent applies local quality by targeting only the specific frequency regions where interference occurs, identified through spectral repetition interval estimation. Rather than applying broad-spectrum suppression that would affect all frequencies, the method selectively synthesizes and subtracts interference only at the estimated spectral repetition frequencies. This localized approach preserves the integrity of desired signals at other frequencies while effectively removing interference

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs feedback by continuously estimating the spectral repetition interval of the interference signal and adjusting the interference reference signal generation accordingly. The system monitors the received signal, identifies interference patterns through spectral analysis, and dynamically updates the interference model to match changing interference conditions. This feedback loop ensures accurate interference cancellation while preserving desired signals that may vary in frequency and characteristics

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4152651B1Signal processor for a radio receiver
Publication Date: 2025.09.03 NXP BV
  • EP4152651B1 patent drawingFigure 1~2
  • EP4152651B1 patent drawingFigure 3~4
  • EP4152651B1 patent drawingFigure 5~6

AI summary

A signal processor and method of signal processing for a radio receiver is described. An input signal is received together with a spectral repetition interval value of an interferer signal. An interference reference signal is generated from the received spectral repetition interval value and the received signal. The received signal is adapted using the generated interference reference signal.