Synchronization Peak Detection in OFDM Receivers
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Solution Overview
Problem
In orthogonal frequency division multiplexing (OFDM) systems, the presence of frequency offsets leads to multiple peaks in the autocorrelation signal, making it difficult for user equipment (UE) to achieve proper synchronization, resulting in increased receiver complexity and energy consumption.
Innovation Solution
A method and apparatus that use a single matched filter with multiple assumed frequency offsets to identify the correct peak in the autocorrelation output, and verify the peak at specific locations based on the synchronization signal properties, reducing the need for multiple matched filters and simplifying the receiver design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple matched filters with different frequency offsets are used to handle frequency offsets, then synchronization accuracy is improved, but device complexity and energy consumption increase
Solution Approach 1:
The patent combines multiple matched filters with different frequency offsets into a single matched filter by processing the received signal through one filter and then adjusting the frequency offset in the signal processing stage. This merging approach maintains the ability to handle multiple frequency offsets while reducing the number of physical filter components needed in the receiver.
Solution Approach 2:
The patent changes the frequency offset parameter dynamically during signal processing. Instead of having multiple fixed filters for different frequency offsets, the system uses a single filter and adjusts the frequency offset parameter in the processing stage, allowing the same hardware to adapt to different frequency conditions without increasing physical complexity.
2Measurement precision
If multiple matched filters with different frequency offsets are used to handle frequency offsets, then synchronization accuracy is improved, but energy consumption increases
Solution Approach 1:
The patent combines multiple matched filters with different frequency offsets into a single matched filter by processing the received signal through one filter and then adjusting the frequency offset in the signal processing stage. This merging approach maintains the ability to handle multiple frequency offsets while reducing the number of physical filter components needed in the receiver.
Solution Approach 2:
The patent changes the frequency offset parameter dynamically during signal processing. Instead of having multiple fixed filters for different frequency offsets, the system uses a single filter and adjusts the frequency offset parameter in the processing stage, allowing the same hardware to adapt to different frequency conditions without increasing physical complexity.
3Reliability
If multiple matched filters are used to handle frequency offsets, then detection probability is improved, but the number of components increases
Solution Approach 1:
The patent combines multiple matched filters with different frequency offsets into a single matched filter by processing the received signal through one filter and then adjusting the frequency offset in the signal processing stage. This merging approach maintains the ability to handle multiple frequency offsets while reducing the number of physical filter components needed in the receiver.
Data Source
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AI summary
Methods and apparatus for identifying correct peaks in outputs of matched filters in user equipment for communication systems are provided. A received signal is correlated with a replica of a synchronization signal, thereby producing a correlation output signal. Peaks are detected in the correlation output signal. The peak is tested at a plurality of predetermined locations that are based on properties of the synchronization signal, thereby producing a plurality of peak test signals. The maximum of the peak test signals is determined.