Wake-Up Packet Preamble Signaling for Low-Power Wireless Latency
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Solution Overview
Problem
Existing wireless communications technologies face a trade-off between power consumption and communication delay due to the use of wake-up receivers (WURs), where prolonged sleep states reduce power consumption but increase communication latency.
Innovation Solution
A novel wake-up packet design with efficient preamble sequences, including N consecutive first sequences and a second sequence in a bit logical negation relationship, to indicate different data rates, facilitating precise time synchronization and reduced overheads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the main radio sleeps for a longer time to reduce power consumption, then overall power consumption is reduced, but communication delay increases
Solution Approach 1:
The radio communication function is segmented into two independent parts: a wake-up receiver (WUR) that operates in low-power mode to detect wake-up packets, and a main radio (MR) that remains in sleep state for most of the time. The WUR handles only the critical wake-up function with minimal processing requirements, allowing the MR to stay asleep longer and reduce overall power consumption while maintaining acceptable communication delay through efficient wake-up packet design.
2Use of energy by moving object
If a wake-up receiver is introduced to enable low-power communication, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The complex main radio functionality is extracted and separated from the simple wake-up receiver. The WUR contains only the essential components for receiving wake-up packets (simple correlation detector and threshold comparator), while the main radio with its full communication capabilities operates independently. This extraction allows the WUR to remain simple and low-power, reducing overall device complexity while enabling power-saving operation.
Solution Approach 2:
The wake-up packet uses a simple and efficient preamble sequence design that requires minimal processing. The correlation detector only needs to match the preamble against stored sequences and compare correlation values against thresholds, avoiding complex signal processing. This simple approach reduces the computational burden on the WUR, allowing it to operate with minimal complexity while achieving effective wake-up functionality.
3Reliability
If the preamble sequence is designed with N consecutive first sequences to indicate data rate, then detection success rate improves, but preamble length increases
Solution Approach 1:
The preamble sequence employs different local patterns (first sequence S repeated N times or second sequence M) to encode data rate information. The receiver performs localized correlation matching against these specific patterns rather than requiring the entire preamble to be long. This local quality approach allows reliable detection through pattern recognition while keeping the overall preamble length manageable, as the distinctive patterns provide sufficient detection confidence even in shorter sequences.
Data Source
AI summary
A wake-up packet sending method, including: obtaining, by a sending apparatus, a wake-up packet WUP, where the WUP includes a preamble sequence, and the preamble sequence includes N consecutive first sequences S, where N is an integer greater than or equal to 2 (for example, [S S]), and the N consecutive first sequences S are used to indicate that a data rate used for the WUP is a first value; or the preamble sequence includes a second sequence M, where the second sequence M is used to indicate that a data rate used for the WUP is a second value; and the second sequence M and the first sequence S are in a bit logical negation relationship; and sending the WUP, to wake up a main receiver of a receiving apparatus.