Aditya Dua (@adidua)

I have a Ph.D. in Electrical Engineering from Stanford University, where my dissertation focused on applying optimization methods to resource scheduling problems in networking. After my Ph.D., I worked at Qualcomm for 6 years, designing signal processing algorithms for 3G/4G cellular modems, then led a team of engineers at Proteus Digital Health for 5 years, working on detecting signals from a proprietary ingestible sensor. Currently, I work on health sensing related algorithms at Apple.

Filtering Noise: The Basics (Part 1)

Aditya Dua ● September 17, 2022●3 comments

How do you pull signals out of random noise? This post builds intuition from first principles for discrete-time white Gaussian noise and shows how simple linear FIR filtering (averaging) reduces noise. You’ll get derivations for the output mean, variance and autocorrelation, learn why the uniform moving-average minimizes noise under a unity-DC constraint, and why its sinc spectrum can be problematic. Part 1 of a short series.

Smaller DFTs from bigger DFTs

Aditya Dua ● January 22, 2019●8 comments

A neat DFT puzzle turns into a tour of three useful spectral tricks. Given only an N point DFT black box, the post shows how to recover the N/2 point DFT of a shorter sequence by zero padding, zero interlacing, or repeating the data. Along the way, it highlights why some methods smooth the spectrum, why others replicate it, and how these operations relate to FFT fundamentals.