OOK Wake-Up Signaling Across Variable Cyclic Prefixes

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Solution Overview

Problem

Existing NR and LTE networks face challenges in reducing power consumption of IoT devices due to the high power consumption of OFDM signal receivers, and the introduction of Wake-Up Receivers (WUR) has not adequately addressed this issue, particularly in NR paging scenarios where demodulation performance is affected by varying cyclic prefixes.

Innovation Solution

A communication method that generates and demodulates OOK signals by adapting to different cyclic prefixes through predefined rules or indications, ensuring consistent demodulation performance by uniformly removing cyclic prefixes based on a short prefix, thereby reducing power consumption and maintaining demodulation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a WUR receiver uses envelope detection to reduce power consumption, then power consumption is reduced to tens to hundreds of microwatts, but demodulation performance deteriorates when cyclic prefix lengths vary

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

Solution Approach 1:

The patent applies preliminary action by pre-defining the cyclic prefix removal rule at the network side before signal transmission. The network device determines the cyclic prefix type according to a predefined rule and removes the cyclic prefix accordingly, then transmits the processed signal to the terminal. This ensures the terminal receiver can directly use envelope detection without needing to perform complex cyclic prefix type judgment, thus maintaining both low power consumption and reliable demodulation performance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism where the network device acts as the mediator that processes the signal before transmission. The network device removes the cyclic prefix based on predefined rules and transmits the pre-processed signal to the terminal. This intermediary processing at the network side enables the terminal's simple envelope detector to achieve reliable demodulation without consuming high power

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the terminal device performs blind detection of cyclic prefix types, then adaptability to different cyclic prefixes is improved, but power consumption and processing complexity increase

Engineering Contradiction:
Improvecyclic prefix compatibilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the cyclic prefix removal function from the terminal device and relocates it to the network device. The network device determines the cyclic prefix type according to a predefined rule and removes the cyclic prefix before transmission. This extraction eliminates the need for the terminal to perform complex blind detection, achieving both cyclic prefix compatibility and low power consumption at the terminal

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The network device provides self-service by automatically determining and removing the cyclic prefix based on predefined rules without requiring complex terminal processing. The network side handles the adaptive processing itself, enabling the terminal to simply receive and demodulate the pre-processed signal with minimal power consumption

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4683278A1Communication method, network device, terminal device and communication system
Publication Date: 2026.01.21 HUAWEI TECH CO LTD
  • EP4683278A1 patent drawingFigure 1~2
  • EP4683278A1 patent drawingFigure 3
  • EP4683278A1 patent drawingFigure 4

AI summary

Embodiments of this application are applicable to the field of communication technologies, and provide a communication method, a network device, a terminal device, and a communication system. The method includes: A network device sends a generated M-bit OOK signal to a terminal device, where M indicates a quantity of OOK symbols carried in each OFDM symbol, a level in time T at an end of each OFDM symbol is the same as a level of a 1st OOK symbol in each OFDM symbol, duration of the 1st OOK symbol is the time T shorter than duration of another OOK symbol in each OFDM symbol, the OFDM symbol includes a first cyclic prefix or a second cyclic prefix, and the first cyclic prefix is shorter than the second cyclic prefix. According to this method, in a process of demodulating the OOK signal by the terminal device, no additional time offset is introduced due to cyclic prefixes with different lengths, so that demodulation performance of the OOK signal can be ensured.