Wireless Receiver Preamble Correlation for Signal Distortion Compensation
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Solution Overview
Problem
Wireless communication systems face challenges in accurately synchronizing receivers due to signal distortions caused by multipath channels, which introduce uncertainty and errors in identifying the beginning of data portions of signals.
Innovation Solution
A method that involves correlating the received signal with a preamble to identify channel characteristics, configuring a digital filter to compensate for these distortions, and using a second preamble correlation to refine timing accuracy by processing the filtered signal to accurately identify the start of data portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a receiver performs preamble correlation on the received signal to synchronize, then the receiver can identify the beginning of the data portion, but multipath channel distortion introduces uncertainty and errors into the synchronization
Solution Approach 1:
The patent applies preliminary action by performing a first preamble correlation before the main synchronization process to identify the approximate location of the preamble portion. This preliminary identification allows the system to extract channel characteristics and configure compensation filters in advance, which then improve the accuracy and reliability of the second preamble correlation used for final synchronization.
Solution Approach 2:
The patent implements feedback by using the output of the first preamble correlation to determine channel characteristics (such as delay spread), which then feeds back into configuring a digital filter to compensate for these characteristics. This compensated filter is applied to the received signal before the second preamble correlation, creating a feedback loop that improves synchronization reliability based on previously detected channel conditions.
2Measurement precision
If the received signal is filtered to compensate for channel characteristics, then timing accuracy is improved, but additional signal processing steps increase device complexity
Solution Approach 1:
The system performs preliminary channel characterization through the first preamble correlation and uses this information to pre-configure the digital filter before the main timing measurement. This preliminary preparation allows the filter to be optimized for the specific channel conditions, improving timing accuracy while keeping the processing pipeline efficient by avoiding real-time filter adjustments during the critical measurement phase.
Solution Approach 2:
The system uses the received signal itself to determine the channel characteristics needed for filter configuration. By extracting delay spread and other channel parameters from the preamble portion of the received signal, the system performs self-characterization without requiring external calibration or additional reference signals, thereby improving timing accuracy without proportionally increasing device complexity.
Data Source
AI summary
A method for operating a receiver in a wireless communication system to synchronize the receiver to a received signal. The received signal is preamble correlated to identify a preamble portion of the signal. Portions of the received signal near the identified preamble portion are processed to determine signal-distorting channel characteristics, such as multipath channel delay spread, of the channel over which the received signal propagated. A digital filter is configured based on the determined channel characteristics to compensate for the signal-distorting channel characteristics, and the received signal is filtered with the configured digital filter. The filtered received signal is second preamble correlated with a second preamble that is different than the first preamble to produce a second preamble correlation. The second preamble correlation is processed to identify delay in the filtered received signal. Portions of the filtered received signal are identified and processed based on the identified delay.