LP-WUR PSS Detection via Frequency-Domain Processing

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Solution Overview

Problem

Low Power Wake Up Receivers (LP-WUR) face challenges in decoding Primary Synchronization Signals (PSS) due to limited bits and small dynamic range, require reducing preamble overhead, linking PSS and LPWUS for cell identification, supporting continuous monitoring, and increasing TX diversity in wireless communication systems.

Innovation Solution

Implementing signal processing techniques such as frequency-domain approaches, adaptive filtering, and noise cancellation to enhance PSS detection, using different symbol coding schemes for preamble and data payload, and incorporating Quadrature Sinusoidal Components to improve decoding performance, while managing LPWUR monitoring with pre-defined search spaces and prohibit timers to reduce false alarms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If LP-WUR uses simple receiver architecture with limited bits and small dynamic range, then power consumption is reduced, but PSS detection capability deteriorates

Engineering Contradiction:

Improvepower consumptionVSAvoidPSS detection capability

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent replaces time-domain signal processing with frequency-domain processing in the LP-WUR. By transforming the received signal into the frequency domain, the system can achieve better PSS detection capability without requiring complex time-domain processing operations, thus maintaining low power consumption while improving detection performance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the processing domain from time-domain to frequency-domain, fundamentally altering how the LP-WUR analyzes signals. This parameter change enables the use of simpler processing operations that are more suitable for low-power devices while maintaining or improving detection capability through frequency-based analysis.

Inventive Principle:

Principle #35Parameter changes

2Speed

If LP-WUR monitors continuously for LP-WUS, then responsiveness is improved, but false alarm rate increases

Engineering Contradiction:

ImproveresponsivenessVSAvoidfalse alarm rate

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent introduces a prohibit timer that prevents the LP-WUR from monitoring for a certain period after detecting an LP-WUS. This preliminary action of setting a monitoring prohibition period reduces false alarms by preventing immediate re-monitoring that could trigger spurious wake-ups, while still allowing rapid response to genuine wake-up signals through proper timing management.

Inventive Principle:

Principle #10Preliminary action

3Speed

If LP-WUR monitors continuously for LP-WUS, then responsiveness is improved, but power consumption increases

Engineering Contradiction:

ImproveresponsivenessVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic monitoring with controlled duty cycles rather than continuous monitoring. The LP-WUR monitors for LP-WUS at specific periodic intervals determined by configuration parameters, which reduces power consumption by keeping the receiver in low-power states between monitoring occasions while maintaining adequate responsiveness through timely periodic checks.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The prohibit timer serves as a preliminary action that controls the monitoring schedule by preventing immediate re-monitoring after a wake-up event. This timing control mechanism optimizes the balance between responsiveness and power consumption by ensuring the LP-WUR doesn't waste energy on redundant monitoring operations.

Inventive Principle:

Principle #10Preliminary action

4Device complexity

If LP-WUR uses existing PSS for timing synchronization, then device complexity is reduced, but cell identification capability deteriorates

Engineering Contradiction:

Improvesynchronization mechanismVSAvoidcell identification

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes the existing PSS serve multiple functions: both timing synchronization and cell identification. By utilizing the same synchronization signal for both purposes, the system reduces device complexity while maintaining cell identification capability through the multi-functional use of the PSS, eliminating the need for separate identification mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20240340794A1Method and apparatus for synchronizing timing of low power wakeup signal and activating/deactivating low power wakeup signal monitoring

Publication Date: 2024.10.10 MEDIATEK INC

AI summary

A communication apparatus includes a low power wakeup receiver (LP-WUR) and a processor. The processor is configured to receive signals from a network apparatus via the LP-WUR, and perform operations including: receiving at least one synchronization signal sent by the network apparatus, wherein the at least one synchronization signal comprises at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS); and using the at least one synchronization signal to detect timing of a low power wakeup signal (LP-WUS).