Transceiver Gain Feedback for Transmit Spur Mitigation
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Solution Overview
Problem
Wireless communication devices face issues with spurious RF emissions causing spectral mask violations and adjacent channel interference due to harmonics and interference from components like baseband phase-locked loops and local oscillators, leading to EVM degradation.
Innovation Solution
A transceiver dynamically adjusts gains across circuitry by monitoring for spectral mask violations using a feedback path, employing a look-up table to mitigate spurious emissions, allowing online spur detection and mitigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If dynamic gain adjustment is implemented to mitigate spectral mask violations, then spurious emissions are reduced and spectral compliance is improved, but device complexity increases due to feedback path and look-up table mechanisms
Solution Approach 1:
The patent implements a feedback mechanism where the transceiver monitors spectral mask compliance and dynamically adjusts gain settings based on real-time measurements. The feedback path allows the system to detect when spurious emissions exceed spectral mask limits and automatically modify operating parameters to reduce these harmful emissions, thereby resolving the contradiction between emission control and system complexity through automated closed-loop control
Solution Approach 2:
The patent employs parameter changes by utilizing a look-up table that stores pre-calculated gain settings for different operating conditions. When spectral mask violations are detected, the system changes operational parameters (gain values) by retrieving appropriate settings from the look-up table, enabling rapid adaptation without complex real-time calculations and thus managing device complexity while effectively reducing spurious emissions
2Reliability
If real-time spectral mask monitoring is implemented, then spectral compliance is ensured, but processing requirements and time consumption increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing gain settings in a look-up table before actual transmission occurs. This allows the system to quickly retrieve appropriate gain values during operation without performing complex real-time computations, thus ensuring spectral compliance through rapid parameter adjustment while minimizing processing time and computational burden
3Object-generated harmful factors
If gain adjustment is made to reduce spurious emissions, then spectral mask violations are mitigated, but EVM performance may be affected under varying operating conditions
Solution Approach 1:
The patent resolves this contradiction through parameter changes by utilizing a look-up table that contains pre-optimized gain settings for different operating conditions. The system selects appropriate gain values from the table based on current operational parameters, enabling spurious emission reduction while maintaining EVM performance through pre-calculated optimal settings that balance both objectives
Solution Approach 2:
The patent implements dynamics by making the gain settings adaptive rather than fixed. The system dynamically adjusts which look-up table entries are applied based on real-time monitoring of spectral mask compliance and operating conditions, allowing optimal balance between spurious emission reduction and EVM performance maintenance across varying scenarios
Data Source
AI summary
Aspects of the present disclosure provide techniques and apparatus for transmit spur mitigation. An example method of signal transmission by a transceiver generally includes outputting a first signal from a transmit chain in a first state, determining that a power associated with the first signal violates a spectral mask, and outputting a second signal from the transmit chain in a second state in response to the determination, the second state being different from the first state.