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Check out the new set of lessons on frequency-domain descriptions for systems.  This series of two lessons, one for continuous-time and one for discrete-time linear time invariant systems, ties together the commonly used tools for describing system behavior.  We show how the impulse response, difference (differential) equation, system (transfer) function are all related to the […]

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 […]

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 […]

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 […]

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 […]

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 […]