Programmable Adaptive Filter for 3G Receiver Spur Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of RF, BB, and PMU components in a single chip for mobile devices leads to significant EMI interference, particularly in 3G receivers, due to digital circuitry noise and clock spurs, which degrades receiver sensitivity and increases manufacturing costs when traditional mitigation techniques fail to completely eliminate these issues.
Innovation Solution
A radio transceiver with a programmable adaptive filter and FFT-based spur identification, dynamically generating notches to suppress narrowband clock spurs and jammers within the 3G receiver's passband, using a Finite Impulse Response digital filter and High Pass Filter configuration, to improve immunity to EMI and maintain sensitivity performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If RF, BB, and PMU components are integrated in a single chip, then manufacturing cost is reduced and device area is minimized, but EMI interference and clock spurs increase significantly
Solution Approach 1:
The patent extracts and removes specific harmful frequency components (clock spurs and narrowband jammers) from the received signal using digital signal processing techniques. The baseband processor identifies and eliminates these spurs through notching in the frequency spectrum, separating the harmful signals from the useful RF signal to restore receiver sensitivity while maintaining the integrated chip architecture.
Solution Approach 2:
The patent introduces an intermediary digital filtering mechanism between the RF front-end and the baseband processor. This intermediary layer, implemented through programmable filters and spectral analysis tools, mediates the EMI interference by detecting and attenuating harmful frequencies before they affect the final signal processing, thus protecting the receiver without requiring physical separation of components.
2Object-affected harmful factors
If traditional EMI mitigation techniques are used, then some interference is reduced, but receiver sensitivity is completely eliminated and manufacturing costs increase
Solution Approach 1:
The patent applies partial action by selectively removing only the most significant harmful frequency components rather than attempting to filter all possible interference. The baseband processor identifies and removes only those spurs and jammers that exceed threshold levels and would severely impact receiver sensitivity, thereby achieving adequate mitigation while preserving receiver performance and avoiding excessive processing complexity.
Solution Approach 2:
The patent implements dynamic adaptation by making the EMI mitigation process configurable and responsive to actual interference conditions. The baseband processor can dynamically adjust filtering parameters, select which spurs to remove, and adapt to changing signal environments, allowing the system to optimize between interference rejection and sensitivity preservation based on real-time conditions rather than using fixed, overly aggressive filtering.
3Object-affected harmful factors
If digital signal processing is applied to remove clock spurs, then EMI immunity is improved, but processing complexity and die area increase
Solution Approach 1:
The patent applies partial action by implementing EMI mitigation through the existing baseband processor functionality rather than adding dedicated hardware for each mitigation function. The same digital signal processing resources used for normal signal processing are leveraged to identify and remove spurs, avoiding duplication of processing complexity while achieving enhanced EMI immunity.
Data Source
AI summary
A radio transceiver including—an antenna (201) switch having a control lead (226); —a RF and front end circuit (202) coupled to said antenna switch and operating in at least one 2G mode and at least one 3G mode; —a RF transceiver (209) coupled to said RF front end and operating in at least a first 2G and a second 3G mode; —a baseband (210) communicating with a set of peripherals and external devices; The radio transceiver is characterized by the fact that it includes: —control means (221) for controlling said antenna switch (201) in a isolated mode; —an programmable adaptive filter controlled by said control means for the purpose of introducing at least one notch for eliminating one corresponding spur. The radio transceiver preferably includes means (215) for performing, under control of said control means (221) a FFT computation for the purpose of elaborating a representation, in the time domain, of the different spurs and/or jammers spoiling the received signal when in isolated mode.