Envelope-Based Symbol Timing Estimation for Constant Envelope Signals

Solution Overview

Problem

Existing symbol timing estimation methods for constant envelope signals, such as phase modulated signals, face challenges in accuracy and power consumption, particularly when relying on rising edge detection, leading to errors and inefficiencies in backscatter communication systems.

Innovation Solution

The use of an envelope detector to detect amplitude ripple in nominal constant envelope signals, enabling accurate symbol timing estimation throughout the data frame duration, which allows for low-power operation and efficient backscatter communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If rising edge detection is used for symbol timing estimation, then timing accuracy can be achieved, but power consumption increases and error accumulation occurs

Engineering Contradiction:

Improvesymbol timing accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the envelope information from the received signal using an envelope detector, discarding the phase and frequency components. This extraction of essential timing information without processing the entire signal reduces computational complexity and power consumption while maintaining timing estimation capability through amplitude ripple detection

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a simple envelope detector followed by basic signal processing (bandpass filtering and peak detection) instead of complex timing estimation algorithms. This uses simpler, lower-power components to achieve the timing estimation function, trading algorithmic complexity for hardware simplicity and energy efficiency

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If high bandwidth processing is used for accurate timing estimation, then measurement precision improves, but device complexity and power consumption increase

Engineering Contradiction:

Improvesymbol timing estimation accuracyVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the envelope information from the received signal using an envelope detector, discarding the phase and frequency components. This extraction of essential timing information without processing the entire signal reduces computational complexity and power consumption while maintaining timing estimation capability through amplitude ripple detection

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex digital signal processing mechanisms with simpler analog/envelope-based detection. By using an envelope detector and basic bandpass filtering instead of sophisticated timing algorithms, the system reduces processing complexity while maintaining timing estimation accuracy through amplitude ripple analysis

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If envelope detection is used for symbol timing estimation, then power consumption is reduced, but timing accuracy may be compromised

Engineering Contradiction:

Improvepower consumptionVSAvoidsymbol timing accuracy

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from phase-based (traditional) to amplitude-based (envelope) detection. By monitoring amplitude ripples in the envelope signal instead of phase transitions, the system achieves timing estimation with reduced power consumption. The amplitude ripple characteristics are exploited to maintain timing accuracy while using simpler, lower-power detection mechanisms

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a simple envelope detector followed by basic signal processing (bandpass filtering and peak detection) instead of complex timing estimation algorithms. This uses simpler, lower-power components to achieve the timing estimation function, trading algorithmic complexity for hardware simplicity and energy efficiency

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP4730726A1Systems and methods for estimating symbol timing in received data frames

Publication Date: 2026.04.22 HAILA TECHNOLOGIES INC

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AI summary

There is provided a method and a circuit for estimating symbol timing in one or more received data frames of a nominal constant envelope signal. The circuit may include an envelope detector and a symbol timing estimator. The envelope detector may be configured to generate an envelope detection output for the received data frames, the envelope detection output having an amplitude ripple associated with the symbol timing in the received data frames. The symbol timing estimator may be configured to receive the envelope detection output and generate a symbol timing estimation output based on the amplitude ripple.