
Accession Number : AD0664326
Title : SIGNAL ENERGY DISTRIBUTION IN TIME AND FREQUENCY.
Descriptive Note : Rept. for 1 Oct 661 Oct 67,
Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
Personal Author(s) : Rihaczek,A. W.
Report Date : OCT 1967
Pagination or Media Count : 29
Abstract : The Fourier representation of signals and its relation to the signal structure in time and frequency, and more generally the inherent properties of phasemodulated signals, have received considerable attention in the past. These topics have led to such seemingly unrelated studies as the representation of a signal in a combined timefrequency plane, 'instantaneous power spectra', and the ambiguity function and its transform relations. It is shown in this paper that the studies can be unified by the introduction of the concept of the complex energy density function of a signal. The function is an extension and combination of the onedimensional energy density functions in time and frequency, the energy density spectrum (the absolute value of psi(f)) squared, and energy density waveform (the absolute value of psi(t)) squared. On the basis of the complex energy density function, the significance of complicatedappearing transform relations is readily understood. The new concept also conveys a good insight into the internal structure of phasemodulated signals. (Author)
Descriptors : (*FOURIER ANALYSIS, INTEGRAL TRANSFORMS), TIME, FREQUENCY, SIGNALS, POWER SPECTRA, ENERGY, EXPONENTIAL FUNCTIONS, FREQUENCY MODULATION, WAVE PROPAGATION, CORRELATION TECHNIQUES, RESPONSE
Subject Categories : Statistics and Probability
Distribution Statement : APPROVED FOR PUBLIC RELEASE