Receiver Chain Gain Selection Under Adjacent Channel Saturation
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Solution Overview
Problem
Existing wireless receiver chains face challenges in selecting optimal gain settings, particularly when dealing with saturation caused by adjacent channel or out-of-band interference, which can lead to signal distortion and compromised integrity due to the suppression of signal power by analog low-pass filters.
Innovation Solution
The method involves bypassing a filter portion of the receiver chain to sample a bypass receive signal, determining saturation levels, and adjusting the gain settings accordingly to prevent saturation, using existing ADC output to assess gain stages without additional signal measurements, and employing I and Q components to diagnose and adjust gain settings efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If higher gain settings are used in receiver chain blocks such as the LNA to minimize thermal noise and improve signal quality, then signal quality is improved, but saturation can result and signal integrity is compromised
Solution Approach 1:
The system performs preliminary saturation detection by monitoring the ADC output before final signal processing. By detecting saturation conditions in advance through the ADC output monitoring, the system can adjust gain settings proactively to prevent signal integrity compromise while maintaining optimal signal quality.
Solution Approach 2:
The system uses feedback from ADC output monitoring to dynamically adjust receiver chain gain settings. The monitored ADC output provides real-time information about saturation conditions, which feeds back to the gain control mechanism to optimize the balance between signal quality and saturation prevention.
2Measurement precision
If ADC output is monitored to detect saturation when there is no adjacent channel or out-of-band interference, then saturation detection is accurate, but when there is adjacent channel interference, the analog low pass filters suppress signal power resulting in low signal measurement at ADC output thereby preventing accurate detection of saturation
Solution Approach 1:
The system extracts the saturation detection function from the filtered signal path and implements it at the ADC output stage. By taking out the saturation monitoring from the analog filter path and placing it at the digital ADC output, the system avoids the signal suppression issue caused by analog low-pass filters while maintaining accurate saturation detection capability.
3Measurement precision
If additional signal measurements are added to assess gain stages accurately, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The ADC output monitoring serves multiple functions simultaneously: it provides both the primary digitization function and the saturation detection function. By making the ADC output monitoring multi-functional, the system achieves accurate gain stage assessment without adding separate measurement circuits, thereby maintaining measurement precision while avoiding increased device complexity.
Data Source
AI summary
Apparatuses, methods and systems of selecting a gain setting of a receiver chain are disclosed. One method includes bypassing a filter portion of the receiver chain and sampling a bypass receive signal while the filter portion of the receiver chain is bypassed. If the sampled bypass receive signal is determined to be saturated greater than a threshold, then selecting a gain setting of the receive chain as a function of the saturation. Further, the filter portion of the receive chain is included while sampling a receive signal with the selected gain setting.