New positioning applications’ availability requirements demand receivers with higher sensitivities and ability to process multiple GNSS signals. Possible applications include acquiring one signal per GNSS constellation in the same frequency band and combining them for increased sensitivity or predicting acquisition of other signals. Frequency domain processing can be used for this purpose, sinc...

This paper presents a study of the Modified Discrete Cosine Transform (MDCT) and its implications for audio coding and error concealment from the perspective of Fourier frequency analysis. A relationship between the MDCT and DFT via Shifted Discrete Fourier Transform (SDFT) is established, which provides a possible fast implementation of MDCT employing an FFT routine. The concept of Time Domain...

It is important to develop a high-performance FFT processor to meet the requirements of real time and low cost in many different systems. So a radix-2 pipelined FFT processor based on Field Programmable Gate Array (FPGA) for Wireless Local Area Networks (WLAN) is proposed. Unlike being stored in the traditional ROM, the twiddle factors in our pipelined FFT processor can be accessed directly. Th...

Time-dependent changes of the wind speed, as for example in Hera Campus (East Timor), are analysed by statistical and autocorrelation function time domain frequency spectrum (frequency domain) using Fast Fourier Transform (FFT). The speed can be modelled Weibull distribution function. shows roughly a non-exponential decay with periodicity. power two peaks nearly 1/f nature at high frequencies, ...

A large family of signal processing techniques consist of Fourier-transforming a signal, manipulating the Fourier-transformed data in a simple way, and reversing the transformation. We widely use Fourier frequency analysis in equalization of audio recordings, X-ray crystallography, artefact removal in Neurological signal and image processing, Voice Activity Detection in Brain stem speech evoked...

to date, a number of numerical methods, including the popular finite-difference time domain (fdtd) technique, have been proposed to simulate ground-penetrating radar (gpr) responses. despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the for...

In this paper, we propose a new architecture for the implementation of the N-point Fast Fourier Transform (FFT), based on the Radix-2 Decimation in Frequency algorithm. This architecture is based on a pipeline circuit that can process a stream of samples and produce two FFT transform samples every clock cycle. Compared to existing implementations the architecture proposed achieves double proces...

This paper addresses the problem of merging speech enhancement and coding in the context of an auditory modeling. The noisy signal is rst processed by a fast wavelet packet transform algorithm to obtain an auditory spectrum, from which a rough masking model is estimated. Then, this model is used to re ne a subtractive-type enhancement algorithm. The enhanced speech coe cients are then encoded i...

Simple Cartesian scans, which collect Fourier transform data on a uniformly-spaced grid in the frequency domain, are by far the most common in MRI. But non-Cartesian trajectories such as spirals and radial scans have become popular for their speed and for other benefits, like making motion-correction easier [12]. A major problem in such scans, however, is reconstructing from nonuniform data, wh...

Finite Fourier integrals of functions possessing jumps in value, in the first or in the second derivative, are shown to be evaluated more efficiently, and more accurately, using a continuous Fourier transform (CFT) method than the discrete transform method used by the fast Fourier transform (FFT) algorithm. A ß-spline fit is made to the input function, and the Fourier transform of the set of B-...