LP-WUS Payload Modulation with OOK Overlay Sequences

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Solution Overview

Problem

Existing LP-WUS systems face inefficiencies in power consumption due to the need for SD-based receivers to remain active for the entire LP-WUS duration, especially when conveying information over multiple slots, which increases power consumption and complexity.

Innovation Solution

Modulating an overlay sequence with symbols from a constellation, such as M-PSK, to map information bits to OOK symbols, allowing SD-based detectors to decode the payload using fewer symbols and reducing active time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SD-based receivers remain active for the entire LP-WUS duration to decode information conveyed over multiple slots, then reliable information decoding is achieved, but power consumption increases

Engineering Contradiction:
Improveinformation decoding reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The LP-WUS signal is segmented into multiple ON durations with overlay sequences, allowing the receiver to process information in discrete time segments rather than continuously. This enables the receiver to wake up for specific durations to decode information and then return to low-power mode, reducing overall power consumption while maintaining decoding reliability through sequential processing of multiple slots.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by including pilot symbols in the ON durations before the actual information transmission. These pilot symbols allow the receiver to estimate channel characteristics and prepare for subsequent decoding operations. By performing this preliminary channel estimation during dedicated pilot periods, the receiver can efficiently decode information in subsequent slots without requiring continuous active state, thus reducing power consumption.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If overlay sequences are modulated with constellation symbols to increase data rate, then information capacity improves, but detector complexity increases

Engineering Contradiction:
Improvedata rateVSAvoiddetector complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses overlay sequences as an intermediary element that is modulated with constellation symbols. The overlay sequence acts as a carrier that enables the transmission of multiple bits per symbol through sequence-based modulation. This intermediary approach allows the receiver to use simple sequence detectors that correlate with the overlay sequence, avoiding the need for complex demodulation algorithms while still achieving high data rates through the modulation of the overlay sequence with constellation symbols.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4625915A1Modulation and coding using OOK to form an LP-WUS payload for sequence-based detectors that can provide a time domain efficiency improvement
Publication Date: 2025.10.01 NOKIA TECHNOLOGIES OY
  • EP4625915A1 patent drawingFigure 1A~1B
  • EP4625915A1 patent drawingFigure 2
  • EP4625915A1 patent drawingFigure 3~4

AI summary

A UE receives a WUS payload having a modulated overlay sequence overlaid on encoding for OOK, where the modulated overlay sequence is formed from the overlay sequence modulated with symbols from a constellation, to map information bits to the symbols. The information bits are at least part of the WUS payload. The UE determines a constant phase error corresponding to ON durations of the OOK and that separates received symbols in phase. The UE determines, using at least the constant phase error, individual received symbols corresponding to individual ON durations of the OOK. The UE determines the symbols that were used to modulate the overlay sequence based on the individual received symbols. The UE determines the information bits corresponding to the determined symbols, and determines at least one result based on the information bits.