How Discrete Signal Interpolation Improves D/A Conversion

Rick Lyons

TimelessIntermediate

Earlier this year, for the Linear Audio magazine, published in the Netherlands whose subscribers are technically-skilled hi-fi audio enthusiasts, I wrote an article on the fundamentals of interpolation as it's used to improve the performance of analog-to-digital conversion. Perhaps that article will be of some value to the subscribers of dsprelated.com. Here's what I wrote: We encounter the process of digital-to-analog conversion every day—in telephone calls (land lines and cell phones), telephone answering machines, CD & DVD players, iPhones, digital television, MP3 players, digital radio, and even talking greeting cards. This material is a brief tutorial on how sample rate conversion improves the quality of digital-to-analog conversion.

Summary

Rick Lyons provides a concise tutorial on discrete-time interpolation and how it improves digital-to-analog conversion quality. The paper explains sample-rate conversion methods, interpolation/reconstruction filter design, and practical implementation choices with an emphasis on audio D/A systems.

Key Takeaways

Explain how interpolation and upsampling reduce imaging and improve analog reconstruction in D/A conversion.
Design effective FIR interpolation/reconstruction filters and implement them efficiently using polyphase structures.
Apply sample-rate conversion techniques (upsampling + filtering) to enhance audio D/A performance.
Measure and interpret spectral artifacts (aliasing/imaging) with FFT-based analysis to validate interpolation choices.

Who Should Read This

Intermediate-level DSP engineers, audio engineers, and advanced hobbyists who want practical guidance on using interpolation and sample-rate conversion to improve D/A conversion quality.

TimelessIntermediate

Topics

Audio Processing Multirate Systems Filter Design FFT/Spectral Analysis