Target Short Training Sequence for Fast WLAN Time Synchronization
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Solution Overview
Problem
Current signal transmission methods in wireless local area networks (WLAN) face challenges in achieving fast initial time synchronization due to high calculation complexity and processing overhead in autocorrelation and cross-correlation operations for time synchronization.
Innovation Solution
A method and apparatus that generate a target short training sequence with a specific symbol sequence, allowing only one peak value greater than a preset threshold in the autocorrelation processing result, enabling efficient initial time synchronization by determining the location of this peak value for synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If autocorrelation and cross-correlation processing are performed on the short training sequence for initial time synchronization, then time synchronization can be achieved, but calculation complexity increases and processing time extends
Solution Approach 1:
The patent extracts only the necessary autocorrelation operation from the conventional processing chain, eliminating the cross-correlation step. By designing a target short training sequence with specific autocorrelation properties (single peak above threshold), the system achieves time synchronization using only autocorrelation processing, thereby reducing calculation complexity while maintaining synchronization precision
Solution Approach 2:
The patent changes the parameters of the short training sequence to ensure it produces a unique autocorrelation peak. By carefully designing the sequence structure and amplitude relationships, the autocorrelation function exhibits a single dominant peak that can be easily detected, simplifying the synchronization algorithm and reducing computational burden
2Loss of information
If multiple peak values exist in autocorrelation processing result, then more correlation information is available, but determining the correct synchronization point becomes complex and time-consuming
Solution Approach 1:
The patent introduces asymmetry in the autocorrelation result by designing the target short training sequence to produce a single dominant peak. This asymmetric peak structure makes it easy to identify the correct synchronization point without needing to analyze multiple peaks, thereby reducing the time required to determine the synchronization position while preserving necessary correlation information
3Reliability
If conventional short training sequence is used with repetitive structure, then autocorrelation property is strong for synchronization, but multiple peak values appear in processing result
Solution Approach 1:
The patent modifies the parameters and structure of the short training sequence to achieve a balance between strong autocorrelation properties and unique peak generation. By adjusting the sequence length, amplitude relationships, and structural composition, the target short training sequence produces a single dominant autocorrelation peak that maintains reliability for synchronization while ensuring measurement precision through peak uniqueness
Data Source
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AI summary
Embodiments of the present invention provide a signal transmission method and apparatus, which can implement fast initial time synchronization. The method includes: generating, by a transmit-end device, an initial short training sequence, where the initial short training sequence includes M sub-sequences b, and the sub-sequence b includes N transmission sampling points; determining a quantity of reception sampling points used by a receive-end device when the receive-end device performs autocorrelation processing; generating a symbol sequence according to the quantity of the reception sampling points, where the symbol sequence is represented as {a0,a1,...,ai,...,aK-1}, and generating a target short training sequence according to the symbol sequence and the initial short training sequence, where the target short training sequence is represented as {a0b,a1b,...,aib,...,aK-1b}, so that only one peak value greater than a preset target threshold exists in a processing result obtained through autocorrelation processing that is performed by the receive-end device on the target short training sequence according to a preset rule; and sending a target signal to the receive-end device, where a short training sequence field of the target signal carries a short training sequence symbol, and the short training sequence symbol is used to indicate the target short training sequence.