Interpolator Design: Get the Stopbands Right
Still RelevantIntermediate
In this article, I present a simple approach for designing interpolators that takes the guesswork out of determining the stopbands.
Summary
This article presents a simple, practical method for designing interpolators that removes the guesswork from choosing stopband locations. The author shows how to determine stopbands systematically so engineers can meet aliasing and imaging requirements for multirate systems with predictable filter orders and performance.
Key Takeaways
- Specify stopband edges based on interpolation factor and imaging/aliasing constraints rather than ad-hoc rules.
- Compute required transition widths and filter orders to meet a target alias rejection for a given upsampling ratio.
- Design multistage or polyphase interpolators to minimize complexity while preserving stopband attenuation.
- Validate interpolator performance using spectral analysis (FFT) to confirm imaging suppression and in-band distortion limits.
Who Should Read This
DSP and communications engineers (intermediate) who design interpolators or upsamplers for audio, communications, or multirate systems and need predictable stopband/aliasing control.
Still RelevantIntermediate
Related Documents
- A New Approach to Linear Filtering and Prediction Problems TimelessAdvanced
- A Quadrature Signals Tutorial: Complex, But Not Complicated TimelessIntermediate
- An Introduction To Compressive Sampling TimelessIntermediate
- Lecture Notes on Elliptic Filter Design TimelessAdvanced
- Computing FFT Twiddle Factors TimelessAdvanced
