HowTo
How to Generate White Gaussian Noise
How to Generate White Gaussian Noise
by Matt Donadio
White Gaussian Noise (WGN) is needed for DSP system testing or DSP system identification. Here are two methods for generating White Gaussian Noise. Both rely on having a good uniform random number generator. We will assume that the function "uniform()" returns a random variable in the range [0, 1] and has good statistical properties.
How to Interpolate the Peak Location of a DFT or FFT if the Frequency of Interest is Between Bins
How to interpolate the peak location of a DFT or FFT if the frequency of interest is between bins
by Matt Donadio
Problem
If the actual frequency of a signal does not fall on the center frequency of a DFT (FFT) bin, several bins near the actual frequency will appear to have a signal component. In that case, we can use the magnitudes of the nearby bins to determine the actual signal frequency.
How to Design Minimum-Phase FIR Filters
How to Design Minimum-Phase FIR Filters
by Matt Donadio
Like most things in DSP, there are several methods to create minimum-phase Finite Impulse Response (FIR) filters.
How to Create Oscillators in Software
How to Create Oscillators in Software
by Matt Donadio
Oscillators can be created in software directly, using the "sine" function, or they can be calculated indirectly using several different iterative methods. We survey those methods here.
Notation:
First, let's assume that:
How to Interpolate in the Time-Domain by Zero-Padding in the Frequency Domain
How to Interpolate in the Time-Domain by
Zero-Padding in the Frequency Domain
by Rick Lyons
Performing interpolation on a sequence of time-domain samples is an important (often used) process in DSP, and there are many descriptions of time-domain interpolation (a kind of curve fitting) in the literature and on the Internet. However, there’s a lesser-known scheme used for interpolation that employs the inverse discrete Fourier transform (IDFT). This little tutorial attempts to describe that technique.
