9 min read
EVM: why a clean spectrum can still fail at 64-QAM
A pattern I keep seeing on the bench goes like this. A prototype modem shows a clean spectrum, the signal sits well above the thermal noise floor, and the link budget says there is …
6 pages
Dsp
7 min read
Nyquist is not Shannon: why more samples does not mean more information
Digital engineers are trained to treat “more” as a default win: higher clock rates, wider bandwidths, deeper bit depths. Applied to analog-to-digital conversion, the …
9 min read
Adaptive Filters and Stochastic Gradient Descent: One Update Rule, Two Vocabularies
Modern AI is often framed as a clean break from classical engineering. For anyone who has worked in adaptive signal processing, that framing is misleading. The mathematical spine …
6 min read
Deriving MMSE: what the Wiener filter actually minimizes
The Wiener filter has a clean claim: among all linear filters operating on wide-sense stationary input, it produces the minimum mean-square estimation error. That claim has a …
6 min read
SNR: the number that decides whether a signal survives
Every communication system starts with the same goal: move a signal from one place to another and recover its meaning at the far end. In practice the signal passes through copper, …
5 min read
I Spent Years on Adaptive Filters. I Was Already Training Neural Networks.
I spent years implementing LMS-based equalizers and echo cancellers in telecommunications. Only later did I fully appreciate what I had been doing mathematically: the same family …