This Topic revisits measuring the size of a signal, but rather than
doing this in the time-domain, it is now considered in the
frequency-domain. By considering the natural size of a signal's
spectrum, it is shown that energy in the time-domain is equal to the
energy in the frequency-domain. This has applications for analysing
signals in both domains, but also dealing with the case where the
theoretical calculation of energy in the one-domain is difficult, but is
simpler in the other-domain. Using this method, it is possible to
create a number of useful identities, as shown in the associated
ELEE08021 Sensor Networks and Data Analysis 2 Lectures -- School of Engineering, University of Edinburgh. Copyright James R. Hopgood and University of Edinburgh, Scotland, United Kingdom (UK). 2021.
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