This paper is part 4 in a series of papers about the Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT). The focus of this paper is on spectral leakage. Spectral leakage applies to all forms of DFT, including the FFT (Fast Fourier Transform) and the IFFT (Inverse Fast Fourier Transform). We demonstrate an approach to mitigating spectral leakage based on windowing. Windowing temporally isolates the Short-Time Fourier Transform (STFT) in order to amplitude modulate the input signal. This requires that we know the extent, of the event in the input signal and that we have enough samples to yield a sufficient spectral resolution for our application.This report is a part of project Fenestratus, from the skunk-works of DocJava, Inc. Fenestratus comes from the Latin and means "to furnish with windows".

This paper is part 6 in a series of papers about the Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT). The focus of this paper is on correlation. The correlation is performed in the time domain (slow correlation) and in the frequency domain using a Short-Time Fourier Transform (STFT). When the Fourier transform is an FFT, the correlation is said to be a "fast" correlation. The approach requires that each time segment be transformed into the frequency domain after it is windowed. Overlapping windows temporally isolate the signal by amplitude modulation with an apodizing function. The selection of overlap parameters is done on an ad-hoc basis, as is the apodizing function selection.This report is a part of project Fenestratus, from the skunk-works of DocJava, Inc. Fenestratus comes from the Latin and means, "to furnish with windows".

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Nonlinear phase shift in travelingwave tubes as applied to multiple access communications satellites." [5] 0. Shimbo, "Effects of intermodulation. AM-PM conversion and Abstracf-The best estimation of sampler timing in adaptively equalized systems is examined. First, two previous approaches to the estimation problem are reviewed and are found to have fundamental shortcomings. The first technique sets the timing instants coincident with the peak of the unequalized.system impulse response. Under certain circumstances this technique can produce nulls in the spectrum of the sampled system, thus preventing efficient operation of the equalizer.The second technique sets the timing instants so as to minimize the residual distortion of the equalized system. This does assure proper operation but requires a second equalizer structure and also requires an accurate initial 'estimate of sampler phase which it cannot provide itself.A timing recovery technique based on band-edge component maximization which circumvents these problems is presented. Although the scheme is not optimal, it efficiently and effectively recovers timing in synchronous equalized data communication systems.