Wake-Up Signal Detection Using Offset-Adjusted Correlation Windows
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Solution Overview
Problem
Existing methods fail to correctly detect wake-up signals due to frequency offsets, leading to incorrect detection of sequences in terminal devices, which results in increased power consumption.
Innovation Solution
The method involves using a synchronization signal with a ZC sequence and its conjugate sequence to estimate a time offset caused by frequency offset, adjusting the detection window for wake-up signals, and performing sliding correlation detection without increasing the detection window length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a fixed detection window is used for wake-up signal detection, then power consumption is reduced, but detection accuracy deteriorates when frequency offset exists
Solution Approach 1:
The patent applies dynamics by making the detection window location adjustable rather than fixed. The terminal device dynamically shifts the detection window based on the time offset estimated from the synchronization signal, allowing the system to adapt to frequency offset conditions while maintaining a compact window size for low power consumption.
Solution Approach 2:
The patent changes the temporal parameter of the detection window (its location in time) based on the estimated time offset. By adjusting the window's position rather than its size, the system compensates for frequency offset effects and maintains detection accuracy without increasing power consumption.
2Measurement precision
If the detection window length is increased to accommodate frequency offset, then detection accuracy improves, but power consumption increases
Solution Approach 1:
The patent segments the detection process into two stages: first, estimate the time offset from the synchronization signal; second, shift the compact detection window by this offset. This segmentation allows accurate detection without needing a large window, thereby avoiding increased power consumption.
Solution Approach 2:
The patent performs preliminary action by estimating the time offset from the synchronization signal before conducting wake-up signal detection. This preliminary estimation enables the subsequent detection window to be precisely positioned, eliminating the need for an oversized window and keeping power consumption low.
3Device complexity
If correlation detection is performed without frequency offset compensation, then device complexity is low, but detection reliability deteriorates
Solution Approach 1:
The patent performs preliminary time offset estimation using the synchronization signal before wake-up signal detection. This preliminary step enables reliable detection under frequency offset without significantly increasing complexity, as it reuses existing synchronization procedures.
Solution Approach 2:
The patent implements feedback by using the estimated time offset from the synchronization signal to adjust the detection window position for wake-up signal detection. This feedback loop compensates for frequency offset effects and improves detection reliability while maintaining manageable system complexity.
Data Source
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AI summary
This application provides a signal transmission method and an apparatus. The method includes: A terminal device receives a synchronization signal from a network device. The synchronization signal is generated based on a synchronization sequence, the synchronization sequence includes a first ZC sequence and a conjugate sequence of the first ZC sequence, or the synchronization sequence includes a sum of the first ZC sequence and the conjugate sequence of the first ZC sequence. The terminal device detects a wake-up signal based on the synchronization signal. By implementing the foregoing method, the terminal device can perform time synchronization based on the synchronization signal, to estimate a time offset of a correlation peak offset caused by a frequency offset of the synchronization signal. The terminal device adjusts, based on the time offset, a location of a detection window of correlation detection corresponding to the wake-up signal, to implement sliding correlation detection on the wake-up signal based on a low-complexity detection window without increasing a length of the detection window. This reduces power consumption of the terminal device.