Synchronization Method Insensitive to Power Variations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing synchronization algorithms in data communication systems are sensitive to gain adjustment inaccuracies, affecting the precision of time synchronization in OFDM signals, particularly in wireless communication systems where power variations between data frames are common.
Innovation Solution
A method that determines a total correlation signal by correlating the incoming signal with a correlation symbol formed of N repetitions of a correlation sequence, identifies a peak in the total correlation signal, and validates synchronization by comparing the power of a partial correlation signal to defined thresholds, reducing sensitivity to gain inaccuracies and improving synchronization detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a classic synchronization algorithm based on autocorrelation is used, then the synchronization time can be determined, but the algorithm is sensitive to gain adjustment inaccuracies and power variations between frames
Solution Approach 1:
The patent divides the correlation process into two separate components: a total correlation signal that provides the primary synchronization peak detection, and a partial correlation signal that validates the synchronization at multiple peak positions. This segmentation allows the system to use the total correlation for initial detection while the partial correlation provides robustness against power variations by validating multiple discrete peak positions independently.
Solution Approach 2:
The patent implements a feedback mechanism where the detected total correlation peak position is used to guide the validation process using partial correlation signals. The system checks for valid peaks at expected positions based on the total correlation result, and only validates synchronization when the partial correlation confirms the expected peak structure. This feedback loop ensures that gain inaccuracies do not lead to false synchronization validation.
2Reliability
If the gain control unit adjusts the gain to work in linear zone, then the analog-to-digital converter operates correctly, but the gain is not precise and depends on estimation accuracy
Solution Approach 1:
The patent changes the approach from relying on precise gain setting to relying on correlation-based detection that is inherently more robust to gain variations. By using correlation signals and validating synchronization based on the structure and relative positions of peaks rather than absolute power levels, the system becomes insensitive to gain estimation inaccuracies while maintaining reliable converter operation.
3Adaptability or versatility
If synchronization algorithm must accommodate power differences from frame to frame, then the system can handle power variations, but the synchronization precision deteriorates
Solution Approach 1:
The patent segments the correlation validation into total correlation for peak position detection and partial correlation for structural validation. This allows the system to accommodate power variations by validating the characteristic peak structure across multiple partial correlation positions without requiring precise knowledge of absolute power levels, thereby maintaining synchronization accuracy despite power differences between frames.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for synchronizing an incoming communication signal in a receiver. Each frame (T) of the signal comprises a learning symbol (SyA) formed of N repetitions of a learning sequence (SeA). The method includes determining a total correlation signal (Tc) by correlating the incoming signal with a correlation symbol formed of N repetitions of a correlation sequence corresponding to all or part of the learning sequence and of duration tsc, and determining a partial correlation signal (Pc) by correlating the incoming signal with the correlation sequence. A peak of the total correlation signal is identified at time tpct. At least one threshold (Sb, Sh) is defined based on the power of the peak of the total correlation signal, and the power of the partial correlation signal is compared to it at times tpct-k*tsc, where k is an integer between 0 and N-1.