Human eyes can only see in the visible part of the electromagnetic spectrum. Radar (Radio Detection and Ranging) is a device that extends our ability to detect the environment far beyond what is allowed by the visual nervous system, see the article on Frequency Modulated Continuous-Wave (FMCW) radars. Today we talk about the idea of pulse compression and the role it plays in target detection. As opposed to a Continuous-Wave (CW) radar, a pulsed radar transmits a short burst of energy followed by a period of silence during which it listens for the echo received from the target. As shown The pos ..read more

Kalman filter is one of the most important but not so well explained filter in the field of statistical signal processing. As far as its importance is concerned, it has seen a phenomenal rise since its discovery in 1960. One of the major factors behind this is its role of fusing estimates in time and space in an information-rich world. For example, position awareness is not limited to radars and self driving vehicles anymore but instead has become an integral component in proper operation of industrial control, robotics, precision agriculture, drones and augmented reality. Kalman filter plays ..read more

The Monty Hall problem is an interesting puzzle loosely based on an American TV game show Let’s make a deal hosted by Monty Hall. While the puzzle looked simple, it perplexed some of the brightest mathematical minds in the United States, including the great Paul Erdäs. This continues to be the case today. In this article, I explore the reason behind what makes this puzzle so unique. The Problem The Monty Hall problem was originally stated and solved in a letter to the journal American Statistician in 1975. However, it went ‘viral’ in 1990 when a reader asked the following question in Ask Maril ..read more

The Bloom’s Taxonomy describes the levels of mastery one attains in a field. Its last two stages are Synthesis and Evaluation. This is where the masters can be differentiated from the experts. In a job interview, for example, a good technique to judge a candidate’s ability is to ask them where the system in question breaks. A little learning is a dangerous thing Drink deep, or taste not the Pierian spring There shallow draughts intoxicate the brain And drinking largely sobers us again While the first two parts of the FMCW radar series addressed the lower levels, Part 3 is where we get into a s ..read more

In Part 1 of FMCW radar series, we described how a radar estimates the range of one or more stationary targets. In Part 2, we talk about estimating the velocities of several moving targets and their directions through forming a structure known as the radar cube. In a wonderful 1991 paper "Wireless Digital Communication: A View Based on Three Lessons Learned", Andrew Viterbi summarizes the Shannon theory for digital communications in the form of 3 lessons, the first of which was the following. "Never discard information prematurely that may be useful in making a decision until after all decisio ..read more

This is Part 1 of a 3-Part series. Sign up here to receive updates on Part 2 and 3. Radar (Radio Detection and Ranging) is an extension of human sensory perception. To understand this idea, consider the following two points. Imagine a bat in a dark night or inside a cave. It utilizes a remarkable method called echolocation to navigate and locate its prey. This involves emitting higher frequency ultrasound waves through their mouth or nose (the transmitter) that bounce off various objects which are then detected by its finely tuned ears (the receivers). This enables the bat to detect even an in ..read more

Alfred North Whitehead said, "Civilization advances by extending the number of important operations which we can perform without thinking of The post How Automatic Gain Control (AGC) Works appeared first on Wireless Pi ..read more

Many signal processing algorithms require computation of the derivative of a signal in real-time. Some of the examples are timing The post Design of a Discrete-Time Differentiator appeared first on Wireless Pi ..read more

Noise is usually considered the main enemy in all DSP applications. This short article briefly describes why noise sometimes plays The post Noise is Not Always the Enemy appeared first on Wireless Pi ..read more

In this article, I describe 5 of the most popular SDRs available for RF experimentation today. We start with a The post Top 5 Software Defined Radios (SDR) for RF Experimentation appeared first on Wireless Pi ..read more