Signal Group Delay Measurement With Time-Frequency Alignment
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Solution Overview
Problem
Conventional signal group delay measurement methods require input and output signals with the same frequency, leading to higher Peak-to-Average Power Ratio (PAPR) and affecting accuracy, and are unable to measure devices with different frequency signals effectively.
Innovation Solution
A method and system that aligns input and output signals in both time and frequency domains to compute signal group delay, allowing for different input and output frequencies while minimizing PAPR, using a signal generation and analysis device with synchronization and a mixer to adjust frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional signal group delay measurement methods are used with multi-tone test signals, then the measurement can be performed, but the PAPR increases which affects measurement accuracy
Solution Approach 1:
The patent changes the signal parameter from multi-tone to single-tone test signals, which fundamentally alters the PAPR characteristics. Single-tone signals have constant amplitude and zero PAPR, eliminating the harmful effect of high PAPR on measurement accuracy while enabling accurate signal group delay measurement.
2Adaptability or versatility
If input and output signals are required to have the same frequency, then conventional measurement methods can be applied, but this limits the ability to measure devices with frequency conversion
Solution Approach 1:
The patent introduces a mixer as an intermediary component that converts the output signal frequency to match the input signal frequency. This mediator enables the measurement system to handle frequency-converting devices by bridging the frequency difference between input and output signals, thereby expanding adaptability without fundamentally complicating the measurement approach.
3Adaptability or versatility
If frequency alignment is performed between input and output signals, then devices with frequency conversion can be measured, but time domain alignment becomes more complex
Solution Approach 1:
The patent performs frequency alignment through mixing before time domain correlation measurement. By pre-converting the output signal frequency to match the input signal frequency, the subsequent time domain alignment becomes straightforward correlation without needing to handle frequency differences, thus reducing overall alignment complexity.
Data Source
AI summary
A signal group delay computation method uses a signal group delay computation system including a signal generation device and a signal analysis device. The signal group delay computation method includes: (a) the signal generation device generates a first input signal to the signal analysis device; (b) the device under test receives the first input signal to generate a first output signal; (c) the signal analysis device performs time-domain alignment on the first output signal and the first input signal to generate a second output signal; (d) the signal analysis device performs frequency alignment on the second output signal and the first input signal to generate a third output signal; and (e) the signal analysis device computes a relative signal group delay based on the first input signal and the third output signal.