Adaptive AGC Mode Switching for Pulsed Interference Rejection

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Solution Overview

Problem

Existing wireless communication networks face performance issues due to unwanted transient signals generated when Automatic Gain Control (AGC) changes state, leading to non-linear distortion and significant loss in link performance, especially in environments with high pulsed interference.

Innovation Solution

A radio network node dynamically decides on AGC modes based on estimated interference scenarios and channel quality, using slow AGC with a longer release timer for stable conditions, fast AGC with a shorter release timer for pulsed interference, and a trigger timer for synchronized interference periods, optimizing AGC behavior to minimize transients and maintain channel stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fast AGC with shorter release timer is used to respond quickly to pulsed interference, then interference rejection is improved, but transient signals and non-linear distortion increase

Engineering Contradiction:
Improveinterference rejectionVSAvoidtransient signals and non-linear distortion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the AGC response time adaptive rather than fixed. The system dynamically adjusts the release timer duration based on detected interference characteristics - using shorter timers for pulsed interference to improve rejection while using longer timers for stable conditions to minimize transients. This dynamic adaptation resolves the contradiction between fast response and transient minimization.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the temporal parameter of the AGC system by introducing multiple release timer configurations. Instead of a single fixed timer value, the system selects between different timer durations (shorter for pulsed interference, longer for stable conditions) based on the interference scenario, thereby optimizing both interference rejection and transient signal reduction.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If slow AGC with longer release timer is used to minimize transients, then signal stability is improved, but response to pulsed interference deteriorates

Engineering Contradiction:
Improvesignal stabilityVSAvoidinterference rejection
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The system dynamically selects between slow and fast AGC modes based on the detected interference scenario. For stable conditions without pulsed interference, the slower AGC with longer release timer is used to maintain signal stability and minimize transients. When pulsed interference is detected, the system switches to fast AGC with shorter release timer, thereby resolving the contradiction between stability and interference rejection through dynamic mode selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the release timer parameter based on operating conditions - using longer timer values for stable conditions to maintain signal integrity and shorter timer values for pulsed interference conditions to improve rejection. This parameter adaptation allows the system to optimize both signal stability and interference rejection for different scenarios.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If fixed AGC mode is used, then system complexity is reduced, but adaptability to different interference scenarios deteriorates

Engineering Contradiction:
ImproveAGC control complexityVSAvoidinterference scenario adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements self-service by enabling the AGC system to automatically detect interference scenarios and select appropriate modes without external intervention. The system monitors the radio frequency environment, identifies pulsed interference characteristics, and autonomously adjusts the release timer duration or switches between AGC modes, thereby achieving adaptability while maintaining relatively simple control architecture.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent creates a universal AGC control mechanism that handles multiple interference scenarios through a single adaptive framework. The system can operate in both fast and slow AGC modes using the same hardware infrastructure, selecting the appropriate mode based on detected interference characteristics. This multi-functionality achieves high adaptability without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3685511B1Radio network node and method therein for deciding AGC mode for a received signal in a wireless communications network
Publication Date: 2021.06.02 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3685511B1 patent drawingFigure 1
  • EP3685511B1 patent drawingFigure 2
  • EP3685511B1 patent drawingFigure 3

AI summary

A method performed by a radio network node for deciding an Automatic Gain Control (AGC) mode to be used for a received signal in a wireless communications network is provided. The radio network node estimates (301) a type of interference scenario affecting the received signal and obtains (302) information about channel quality of channels between the radio network node and connected wireless devices. Based on the estimated type of interference scenario and the obtained information about the channel quality, the radio network node dynamically decides (303) for the received signal, which AGC mode out of the following ACG modes to be used: - a slow AGC using a release timer for releasing an AGC state, - a fast AGC using a release timer for releasing an AGC state, and - a fast AGC using a trigger timer triggering an AGC state a first time interval before an interference period, and the release timer releasing the AGC state a second time interval after said interference period ends.