Receiver Gain Control via Pre-Combination Threshold Comparison
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Solution Overview
Problem
Current automatic gain control systems in radio transceiver devices with array antennas struggle to independently control individual antenna signal paths, leading to signal saturation and distortion in combined received signals, especially in large antenna systems where separate control loops are not feasible.
Innovation Solution
A method and system for automatic gain control that compares RF signals to a threshold before analogue combining, allowing for gain control decisions to be made and notifications sent to detectors, thereby enabling efficient gain control in receivers with analogue combined beam forming, reducing the number of signals between the receiver and gain control to one without affecting functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate control loops are implemented in each receiver branch, then individual antenna signal paths can be controlled, but device complexity increases and becomes infeasible for large antenna systems
Solution Approach 1:
The patent combines multiple antenna signal paths into a single receiver branch using an analog combiner. Instead of having separate control loops for each antenna path, the system merges all RF signals at the analog level before detection, allowing a single control loop to manage the combined signal. This resolves the contradiction by maintaining signal path control reliability through analog combining while avoiding the complexity of multiple separate control loops.
2Device complexity
If multiple RF signals are combined before detection, then the number of detector inputs is reduced, but individual signal path monitoring and gain control become impossible
Solution Approach 1:
The patent implements gain control decisions before the analog combining operation. The controller determines whether to apply gain control to individual RF signals based on threshold comparisons made prior to combining. This preliminary action allows the system to prevent signal saturation and distortion before they occur in the combined signal, maintaining reliability while still achieving the simplification of having a single detector input.
3Device complexity
If gain control is applied after analog combining, then the system is simpler to implement, but signal distortion cannot be prevented
Solution Approach 1:
The patent applies gain control in the analog domain before the signals are combined and detected. The controller adjusts the gain of individual RF signals or the combined signal at the analog level before detection occurs. This preliminary gain control prevents signal saturation and maintains signal quality, while the analog nature of the control keeps the implementation relatively simple compared to digital post-processing solutions.
Data Source
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AI summary
There is provided automatic gain control of radio chains of a receiver. At least two radio frequency (RF) signals are received. Each RF signal is received on an individual radio chain from an antenna array. By comparing the at least two RF signals to a threshold it is determined whether to perform gain control or not of at least one of the at least two RF signals before analogue combining of the at least two RF signals. A notification is sent to a detector regarding whether gain control is performed or not. Analogue combining of the at least two RF signals is performed, thereby generating a single input to the detector.