### Low-Density Parity Check for Modern Communication Systems

This post explores how Low-Density Parity-Check (LDPC) codes work and how they are finding increasing use in communications applications.

### The Art and Science of Capacitive Technologies

This blog post reviews how capacitive touch/sense technologies work and how the Cardinal Peak team adapted the technology to an unusual environment.

### How “Disposable” Bluetooth Changes the User Experience

This blog post assesses how Bluetooth technology that’s cheap enough to be used in disposable products will alter the user’s experience.

### Curious About What an FPGA is and How It Actually Works?

An FPGA is like an older gate array, but the metal interconnections between the gate array logic elements are replaced by SRAM fabric that is infinitely flexible and doesn’t wear out. This fabric allows you to use the same FPGA to implement a myriad of digital circuits. Explore FPGAs and how to address their challenges like reprogramming the SRAM every time you power up.

### R0 and COVID-19: A Simple DSP Perspective

This blog presents — and solves using Z-transforms — a trivial difference equation incorporating the much touted variable R0.

### Negative Zero

My wife brings up the following story any time she wants to make the point that I’m pedantic: When one of my daughters was in second grade, her math teacher told the class that any number divided by zero was one. I dashed off an impassioned email to the teacher, insisting that the result had…

### Introduction to AES67

AES67 is a standard for transport of high performance audio over IP networks. High performance, as AES67 defines it, is at least a 44.1 kHz sampling frequency, at least 16-bit resolution and latency less than 10 ms. AES67 is targeted to applications in professional audio: broadcast, production, live audio and commercial and residential applications. Rather…

### Sometimes, Noise Helps

I’ve been working on a fun problem lately that involves estimating a scalar parameter from a set of repeated observations. It turns out that in certain circumstances, the presence of noise in the system can actually make the estimate more accurate, which is a little counterintuitive and also kind of cool. In my case, I…

### Why Sample Size and Random Sampling Matters

Recently we tweeted an interesting article on big data, from the Financial Times. The author’s key point is that sampling bias and sampling error are possible even with large data sets. As illustration, the author discusses a classic case where the Literary Digest incorrectly predicted that Alf Landon would beat FDR in the 1936 election.…

### Choosing the Correct Video Sampling Format

We’re a little late in posting this, but I wrote a blog entry for EDN last week that discusses how to choose the correct video sampling format. An excerpt: To process signals digitally, they must first be sampled and quantized. Sampling refers to measuring the light intensity at discrete space-time points, while quantization is the…