Timing Recovery Circuit Using Sample Subset Segmentation
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Solution Overview
Problem
Traditional timing recovery circuits in digital receivers face challenges in providing accurate timing recovery for both continuous phase modulation and linear stream modulation, especially at high data rates, due to the need for high processing rates and complexity, and are unable to efficiently operate at a clock rate slower than the data clock.
Innovation Solution
A method that uses a subset of consecutive data samples within each observation period for timing recovery, allowing the circuit to operate at a slower clock rate by processing a continuous snapshot of samples, which reduces processing complexity and cost, and enables timing recovery for both continuous phase modulation and linear stream modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional timing recovery circuits process all data samples at high data rates, then timing recovery accuracy is maintained, but processing complexity and required clock rate increase significantly
Solution Approach 1:
The patent segments the data samples into two distinct groups: a first subset of samples used for timing recovery processing and a second subset of samples used for data recovery processing. This segmentation allows the timing recovery circuit to operate independently at a lower clock rate while maintaining accuracy, as only the necessary subset of samples is processed for timing extraction, reducing overall processing complexity.
Solution Approach 2:
The patent applies partial action by processing only a portion (subset) of the available data samples for timing recovery rather than processing all samples. This partial processing approach maintains sufficient timing recovery accuracy while significantly reducing the processing load and allowing the circuit to operate at a slower clock rate.
2Measurement precision
If traditional timing recovery circuits operate at the data clock rate, then timing recovery is accurate, but the circuit cannot reduce processing rate to lower complexity and cost
Solution Approach 1:
By segmenting samples into timing recovery subset and data recovery subset, the patent enables the timing recovery circuit to operate at a lower clock rate than the data clock rate. The first subset of samples is processed at the timing recovery clock rate, which can be slower than the data clock rate, thus reducing processing rate while maintaining accuracy.
Solution Approach 2:
The patent uses partial action by processing only a subset of samples for timing recovery at a reduced rate. This allows the timing recovery function to operate at a lower productivity level (slower clock rate) while still achieving accurate timing extraction, as the subset of samples contains sufficient timing information.
3Measurement precision
If Fs/4 down-conversion is implemented for both modulation types, then timing recovery is accurate, but circuit complexity increases
Solution Approach 1:
The patent implements a universal timing recovery circuit that can handle both continuous phase modulation and linear stream modulation using the same processing architecture. The circuit uses a single subset of samples for timing recovery that works for both modulation types, eliminating the need for separate processing paths and reducing overall circuit complexity.
Solution Approach 2:
The patent segments the processing function by separating timing recovery processing from data recovery processing. The first subset of samples is dedicated to timing recovery, which can be processed using a simplified architecture that works for both modulation types, while the second subset handles data recovery. This segmentation reduces the complexity required for the timing recovery circuit.
Data Source
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AI summary
A method for providing timing recovery from a received digital data stream where the digital data stream is a series of consecutive data samples. The method separates the data stream into a series of consecutive observation periods where each observation period includes the same number of consecutive data samples. The method also includes identifying a series of consecutive timing recovery data samples in each observation period where the timing recovery data samples are used for timing recovery and other data samples in the observation period are not used for timing recovery, and where the number of data samples used for timing recovery in each observation period is less than the number of data samples that are not used for timing recovery in the observation period. The method then uses the timing recovery data samples for timing recovery in each observation period.