Spectral Error Analysis of Windowed Discrete Sinusoidal Signals

What is it about?

Window functions are often used in most signal measurement equipment in order to improve the accuracy of spectral measurement. Surprisingly, this way may produce great error whenever some measurement parameters are set incorrectly. This fact is explained mathematically and is also evidenced by a simple experiment.

Featured Image

Why is it important?

At least there are two reasons why it is important: 1. The spectral error due to windowing must be controlled by setting several measurement parameters correctly, otherwise the error will be attenuated and leads a fatal misinterpretation about the measured system. 2. The spectral error behavior is already expressed in a mathematical equation. It is a foundation to build an accurate spectral measurement system.