Receiver Sampling Frequency Offset Estimation Using Bootstrap Signals
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Solution Overview
Problem
Conventional receivers supporting ATSC 3.0 face significant estimation errors in sampling frequency offset due to low signal-to-noise ratios and large pilot signal intervals, leading to poor signal quality.
Innovation Solution
A method using a bootstrap signal to estimate sampling frequency offset by performing autocorrelation operations on multiple symbols, generating correlation results, and determining the offset, which is then used to adjust the data signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pilot signals are used to estimate sampling frequency offset, then the receiver can obtain offset estimation, but the estimation error becomes larger when pilot signals have large intervals
Solution Approach 1:
The patent changes the signal type used for estimation from conventional pilot signals to bootstrap signals. Bootstrap signals are specifically designed with properties that make them more suitable for sampling frequency offset estimation, particularly in low SNR conditions. This parameter change (signal type) resolves the contradiction by providing accurate estimation without requiring frequent pilot signals.
Solution Approach 2:
The patent uses the bootstrap signal structure which contains embedded information about the sampling frequency offset. By copying and processing multiple bootstrap signals, the system can achieve accurate estimation without needing closely spaced pilot signals, thus resolving the contradiction between estimation accuracy and pilot signal interval.
2Measurement precision
If conventional pilot signal methods are used, then the receiver can estimate sampling frequency offset, but estimation error increases when signal-to-noise ratio is lower than −7 dB
Solution Approach 1:
The patent converts the harmful effect of low SNR into a benefit by using bootstrap signals that are specifically designed to be robust against noise. The bootstrap signal structure allows the system to extract accurate sampling frequency offset information even when SNR is lower than -7 dB, effectively converting the harmful noise condition into a manageable scenario.
Solution Approach 2:
The patent changes the estimation method from conventional pilot signal correlation to bootstrap signal-based autocorrelation. This parameter change in the estimation algorithm provides immunity to low SNR conditions, allowing accurate offset estimation even when the signal quality is poor.
3Ease of manufacture
If ADC sampling frequency does not match data rate, then the receiver can operate with standard ADC, but sampling frequency offset issue results in poor signal quality
Solution Approach 1:
The patent implements a feedback mechanism where the sampling frequency offset is estimated using bootstrap signals and then used to adjust the sampling frequency. This closed-loop feedback system allows the receiver to maintain good signal quality without requiring precise matching between ADC sampling frequency and data rate, thus resolving the contradiction between ADC compatibility and signal quality.
Solution Approach 2:
The patent dynamically adjusts the sampling frequency parameter based on the estimated offset. By changing the sampling frequency parameter in real-time based on bootstrap signal analysis, the system maintains high signal quality while using standard ADC components that may not have perfectly matched frequencies.
Data Source
AI summary
The present invention provides a method for estimating a sampling frequency offset of a receiver supporting ATSC 3.0 standard is disclosed. The method includes the steps of: receiving a bootstrap signal comprising a plurality of symbols; performing an autocorrelation operation on a first symbol of the plurality of symbols to generate a first correlation result; performing the autocorrelation operation on a second symbol of the plurality of symbols to generate a second correlation result; and determining the sampling frequency offset according to the first correlation result and the second correlation result.