Polyphase Filters and Filterbanks


ALONG CAME POLY Polyphase filtering is a computationally efficient structure for applying resampling and filtering to a signal. Most digital filters can be applied in a polyphase format, and it is also possible to create efficient resampling...

Understanding and Relating Eb/No, SNR, and other Power Efficiency Metrics

Eric Jacobsen

Introduction Evaluating the performance of communication systems, and wireless systems in particular, usually involves quantifying some performance metric as a function of Signal-to-Noise-Ratio (SNR) or some similar measurement. Many systems...

Python scipy.signal IIR Filter Design

Christopher Felton

Introduction The following is an introduction on how to design an infinite impulse response (IIR) filters using the Python scipy.signal package.  This post, mainly, covers how to use the scipy.signal package and is not a thorough...

Python number crunching faster? Part I

Christopher Felton

Everyone has their favorite computing platform, regardless if it is Matlab, Octave, Scilab, Mathematica, Mathcad, etc.  I have been using Python and the common numerical and scientific packages available.  Personally, I have found this...

Bank-switched Farrow resampler

Markus Nentwig

Bank-switched Farrow resampler Summary A modification of the Farrow structure with reduced computational complexity.Compared to a conventional design, the impulse response is broken into a higher number of segments. Interpolation accuracy is...

A Fixed-Point Introduction by Example

Christopher Felton

Introduction The finite-word representation of fractional numbers is known as fixed-point.  Fixed-point is an interpretation of a 2's compliment number usually signed but not limited to sign representation.  It...

Discrete Wavelet Transform Filter Bank Implementation (part 2)

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Following the previous blog entry: http://www.dsprelated.com/showarticle/115.php Difference between DWT and DWPT Before getting to the equivalent filter obtention, I first want to talk about the difference between DWT(Discrete Wavelet...

Discrete Wavelet Transform Filter Bank Implementation (part 1)

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UPDATE: Added graphs and code to explain the frequency division of the branches The focus of this article is to briefly explain an implementation of this transform and several filter bank forms. Theoretical information about DWT can be found...

Multiplierless Exponential Averaging

Rick Lyons

This blog discusses an interesting approach to exponential averaging. To begin my story, a traditional exponential averager (also called a "leaky integrator"), shown in Figure 1(a), is commonly used to reduce noise fluctuations that contaminate...

Music/Audio Signal Processing

Julius Orion Smith III

Greetings,This is my blog from the point of view of a music/audio DSP research engineer / educator. It is informal and largely nontechnical because nearly everything I have to say about signal processing is (or will be) somewhere in my four-book...