Tracking Rejection Filter for Dynamic Range Reduction
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Solution Overview
Problem
Radio receivers in noisy environments face challenges due to increased dynamic range caused by interfering signals, which necessitate higher data rates and clock speeds to transmit and process signals effectively.
Innovation Solution
A tracking and rejection filter system that selects a center frequency based on detected interfering signals, using digital in-phase and quadrature signals to attenuate noise, thereby reducing the dynamic range required for signal transmission and processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a radio receiver operates in a noisy environment with interfering signals, then the received signal contains more information but the dynamic range increases beyond what is needed to represent the desired information
Solution Approach 1:
The patent extracts and removes interfering signals from the received signal before processing. The interference rejection module identifies and separates unwanted signals (such as constant tones or modulated signals) from the desired modulated radio frequency signal, thereby reducing the dynamic range without losing the desired information content.
Solution Approach 2:
The patent introduces an intermediary interference rejection module between the signal receiver and the demodulator. This intermediary component processes the received signal to remove interfering components before the signal is transmitted to external demodulators, thus reducing the dynamic range requirement for subsequent processing stages.
2Loss of information
If the dynamic range of the received signal is increased due to interfering signals, then more information is transmitted but higher data rates and faster clock signals are required
Solution Approach 1:
By extracting and removing interfering signals before transmission to external demodulators, the patent reduces the dynamic range of the signal that needs to be transmitted. This reduction in dynamic range eliminates the need for higher data rates and faster clock signals that would otherwise be required to handle the increased signal complexity.
Solution Approach 2:
The patent performs interference rejection as a preliminary action before the signal is transmitted to external demodulators. By pre-processing the signal to remove interfering components, the system prepares a cleaned signal with reduced dynamic range, thereby avoiding the need for high-speed transmission and processing in subsequent stages.
Data Source
AI summary
A tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.