A series of three lessons on the Fourier series is now available in the Fourier Series and Transforms category. The Fourier series plays an important role in representing periodic, continuous-time signals in the frequency domain. These lessons introduce the definition of the Fourier series and the most important Fourier series properties. There is also an […]

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## Systems Described by Difference Equations: Solutions and Characteristics

Difference equations are a powerful tool for describing and implementing linear time invariant systems. They are one of the few system descriptions that can account for the effect of stored energy when the input is applied. In this new two lesson sequence you will learn a technique for solving difference equations as a sum of […]

## Aliasing of Signals: Identity Theft in the Frequency Domain

A blog post on aliasing has been in the works for some time and is now finished. Check it out at Aliasing of Signals: Identity Theft in the Frequency Domain. The reason aliasing happens with signals is a simple consequence of discrete-time sinusoids of different frequencies not always being unique. Understanding the origin of aliasing […]

## AllSignalProcessing.com Site Updates

We've been busy generating new lessons, and are modifying the site organization slightly to accommodate the new content. In particular, there are new lessons on the way discussing difference and differential system descriptions for linear time-invariant systems, the Fourier series, Fourier transforms for periodic signals, and frequency-domain descriptions for systems described by difference and differential […]

## Estimate the Amplitude and Phase of Sinusoids

Sinusoids play an important role in describing physical phenomena and thus are widely used in signal processing. Check out our blog post on how to estimate the amplitude and phase when the frequencies of the sinusoids are known. Find out why the DFT is not the best solution to this problem and how you can estimate the […]

## Amplifiers and Nonlinear Systems

Amplifiers often exhibit nonlinear behavior, especially when pushed to maximum gain. Nonlinearities introduce distortion into the amplifier output. In particular, intermodulation distortion results at sum and difference frequencies of the input. Nonlinear distortion is very problematic for communication systems, but is exploited creatively by electric guitarists. Find out more and listen to examples of distortion at Nonlinear […]