Adaptive Local Oscillator Quality for Wake-Up Receiver ACI Handling

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Solution Overview

Problem

Wake-up receivers (WURs) face challenges in handling adjacent channel interference (ACI) due to relaxed frequency generation requirements, which lead to reciprocal mixing and degraded performance, making it difficult to maintain low power consumption while ensuring effective interference suppression.

Innovation Solution

Adapting the frequency generation quality of the local oscillator arrangement by using multiple LO generation circuits or adjusting the characteristics of a single circuit to meet performance targets with a small margin, allowing for low power consumption without significant ACI performance degradation, by estimating tolerable frequency generation quality based on carrier-to-interference ratio and phase noise levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If relaxed frequency generation requirements are used in WUR, then power consumption is reduced, but adjacent channel interference handling deteriorates due to reciprocal mixing

Engineering Contradiction:
Improvepower consumptionVSAvoidACI handling performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic adaptation of frequency generation quality by the local oscillator arrangement, allowing it to switch between different quality levels based on operational conditions. This enables the WUR to use relaxed frequency generation (low power) when ACI is not present, and switch to higher quality frequency generation when ACI is detected, thereby resolving the contradiction between power consumption and ACI handling performance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the frequency generation quality parameter of the local oscillator arrangement adaptively. By estimating tolerable frequency generation quality based on carrier-to-interference ratio and phase noise levels, the system adjusts the LO generation characteristics to meet performance targets with minimal power consumption, avoiding the need for consistently high-quality (high power) frequency generation

Inventive Principle:
Principle #35Parameter changes

2Reliability

If narrow-band selectivity filter is implemented in WUR, then selectivity is improved, but power consumption increases due to precise frequency reference requirements

Engineering Contradiction:
ImproveselectivityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent dynamically adjusts the selectivity filter bandwidth based on the presence and strength of adjacent channel interferers. When ACI is detected, the filter bandwidth is narrowed to improve selectivity; when ACI is absent, the filter bandwidth is widened to allow relaxed frequency generation, thereby avoiding the need for continuously high-power precise frequency reference generation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the filter bandwidth parameter adaptively based on estimated tolerable frequency generation quality. This allows the WUR to achieve narrow-band selectivity only when necessary (when ACI is present), while using wider bandwidth filtering (and thus relaxed frequency generation) when ACI is absent, resolving the contradiction between selectivity and power consumption

Inventive Principle:
Principle #35Parameter changes

3Reliability

If high quality frequency generation is used in WUR, then ACI performance is improved, but power consumption increases

Engineering Contradiction:
ImproveACI performanceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a dynamic quality adaptation mechanism where the local oscillator arrangement adjusts its frequency generation quality based on real-time estimation of tolerable quality levels. This allows the system to use high quality frequency generation only when ACI performance is required, and switch to low power relaxed frequency generation when ACI is not present, thereby resolving the contradiction between ACI performance and power consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the frequency generation quality parameter adaptively by estimating tolerable quality based on carrier-to-interference ratio and phase noise levels. This ensures that high quality frequency generation is used only when necessary to meet performance targets, minimizing power consumption while maintaining ACI performance when required

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3596832B1Radio receiver, method and computer program
Publication Date: 2024.09.04 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3596832B1 patent drawingFigure 1~5
  • EP3596832B1 patent drawingFigure 6~8
  • EP3596832B1 patent drawing

AI summary

A radio receiver comprises a local oscillator arrangement and a controller. The local oscillator arrangement is arranged to provide a signal for down-conversion of radio frequency signal to an intermediate frequency or a baseband frequency in the radio receiver, and the local oscillator arrangement is capable of selectably providing multiple frequency generation qualities. The controller is arranged to estimate a tolerable frequency generation quality for the current operation of the radio receiver or determine whether the current operation of the radio receiver is satisfactory in sense of a currently provided frequency generation quality, and based on the estimation or determination adjust frequency generation quality of the local oscillator arrangement by selecting one of the multiple frequency generation qualities. A radio arrangement, a method and a computer program are also disclosed.