Receiver AGC Threshold Switching for Narrowband Carrier Tuning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional Automatic Gain Control (AGC) algorithms in radio receivers are inefficient due to the need for time-consuming power measurements and frequent gain adjustments, leading to high power consumption and potential signal impairments, especially in scenarios where only a portion of the transmission bandwidth is received at a time.

Innovation Solution

Implementing a gain control system that assesses the frequency difference between the current and target carrier frequencies to determine whether to perform a full or optimized AGC algorithm, using gain variability metrics and historical data to optimize gain settings, thereby reducing unnecessary power consumption and signal impairments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full automatic gain control algorithm is performed to ensure accurate gain settings, then gain control reliability is improved, but power consumption and processing time increase

Engineering Contradiction:

Improvegain control reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameter of AGC algorithm complexity based on frequency difference conditions. When frequency difference is small (within threshold), a simplified AGC algorithm is used; when frequency difference is large, a full AGC algorithm is performed. This dynamic parameter adjustment resolves the contradiction by adapting the reliability level to the actual need, reducing power consumption when full reliability is not required.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a full automatic gain control algorithm is performed to ensure accurate gain settings, then gain control reliability is improved, but processing time increases

Engineering Contradiction:

Improvegain control reliabilityVSAvoidAGC processing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent dynamically changes the AGC algorithm complexity parameter based on frequency difference. For small frequency differences, a fast simplified algorithm is used; for large frequency differences, a comprehensive full algorithm is applied. This resolves the time-reliability contradiction by performing detailed processing only when necessary.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If frequent gain adjustments are made to adapt to changing conditions, then adaptability is improved, but signal impairments and power consumption increase

Engineering Contradiction:

Improvegain adaptabilityVSAvoidsignal impairments

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic gain adjustment based on frequency difference conditions. The system adapts its behavior: using simplified adjustment for small frequency changes and full adjustment for large changes. This dynamic approach improves adaptability while avoiding unnecessary adjustments that cause signal impairments.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the gain adjustment strategy parameter based on frequency difference threshold comparison. When frequency difference is within threshold, minimal adjustment is performed; when exceeding threshold, full adjustment is applied. This resolves the contradiction between adaptability and signal quality.

Inventive Principle:

Principle #35Parameter changes

4Reliability

If conventional AGC algorithms are used with worst-case convergence time assumptions, then reliability is improved, but productivity decreases

Engineering Contradiction:

Improveconvergence reliabilityVSAvoidreception efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the convergence time parameter from a fixed worst-case assumption to a dynamic value based on frequency difference. When frequency difference is small, the system uses a simplified algorithm with known faster convergence; when large, it uses the full algorithm with worst-case assumptions. This resolves the reliability-productivity contradiction by optimizing convergence time predictions.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11901926B2Optimization of automatic gain control for narrow bandwidth operation

Publication Date: 2024.02.13 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

The gain of an amplifier in a receiver operating in a cellular communication system is controlled by determining one or more gain variability metrics, which are then used to produce first and second threshold values. A frequency difference between a current carrier frequency and a target carrier frequency is ascertained and then compared to the threshold values. Target gain setting production is based on comparison results: If the frequency difference is larger than the first threshold, a first automatic gain control algorithm is performed; if the frequency difference is smaller than the first threshold and larger than the second threshold, a second automatic gain control algorithm is performed, wherein the second automatic gain control algorithm uses a current gain setting as a starting point; and if the frequency difference is smaller than both the first and second thresholds, the current gain setting is used as the target gain setting.