Wireless Receiver AGC Using Multi-Stage Saturation Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication devices face challenges in implementing a common receiver automatic gain control (RxAGC) logic across multiple radio access technologies (RATs) due to differing settling time targets, leading to reduced throughput, increased latency, and lower transmission range.
Innovation Solution
An improved RxAGC algorithm that employs multiple saturation detectors at different stages of the receive path to detect signal strength and perform one-step coarse gain correction, reducing settling time and improving performance across WWAN and WLAN RATs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a common receiver automatic gain control (RxAGC) logic is implemented across multiple radio access technologies (RATs), then device complexity is reduced and versatility is improved, but settling time targets cannot be met for all RATs leading to reduced throughput and increased latency
Solution Approach 1:
The patent segments the gain control function into two independent parts: a common coarse gain control stage that serves multiple RATs, and a RAT-specific fine gain control stage that handles settling time requirements. This segmentation allows the common logic to handle the bulk of gain adjustment while RAT-specific logic handles the precise timing-critical adjustments, resolving the contradiction between versatility and performance.
Solution Approach 2:
The patent introduces a new dimension to the gain control architecture by adding a fine gain control stage that operates in parallel with the common coarse gain control. This dimensional expansion allows the system to simultaneously satisfy multiple RAT requirements without compromising settling time performance, as the fine control stage can be optimized for each RAT's specific timing requirements.
2Measurement precision
If traditional multi-step AGC algorithms are used, then gain control precision is maintained, but settling time is excessively long causing loss of time
Solution Approach 1:
The patent applies preliminary action by performing coarse gain control first to bring the signal into the acceptable range quickly, before initiating the finer gain adjustments. This preliminaryç²— adjustment reduces the time required for subsequent fine tuning, as the signal is already close to the target level, thereby reducing overall settling time while maintaining precision.
Solution Approach 2:
The patent segments the gain control process into coarse and fine adjustment phases that can operate in parallel or sequence. The coarse gain control handles large adjustments quickly, while the fine gain control handles precise adjustments. This segmentation allows the system to achieve both speed and precision by distributing the workload across different control stages.
3Loss of time
If multiple saturation detectors are deployed at different stages of the receive path, then settling time is reduced through one-step coarse gain correction, but device complexity increases
Solution Approach 1:
The patent segments the detection function across multiple stages of the receive path, placing saturation detectors at strategic points (LNA output, mixer output, baseband output). Each detector monitors a different stage and provides information for coarse gain control. This segmentation allows parallel detection without requiring a single complex detector, achieving fast settling through distributed simple detectors.
Solution Approach 2:
The saturation detectors serve multiple functions: they monitor signal levels at different stages, provide feedback for coarse gain control, and enable parallel operation across multiple RATs. By making the detection system multi-functional, the patent achieves fast settling time without proportionally increasing complexity, as the same detector architecture serves multiple purposes.
Data Source
AI summary
Methods and apparatus for performing automatic gain control in wireless receiver front-end circuitry are described. An example apparatus includes a receiver and control logic coupled to the receiver. The receiver generally includes a receive path including a first amplifier, a second amplifier having an output coupled to an input of the first amplifier, a mixer having an output coupled to an input of the second amplifier, and a third amplifier having an output coupled to an input of the mixer. The receiver also includes a first saturation detector circuit, a second saturation detector circuit, and a third saturation detector circuit. The control logic is configured to control a gain state of the third amplifier, based on one or more respective signals output from at least one of the first saturation detector circuit, the second saturation detector circuit, or the third saturation detector circuit.