163 citations · 1.5k across the 72 of their papers we have counts for
16 papers · 1 filter
32-point DFT Approximations Based on Minimal Frobenius Error and DFT Symmetries
L. Andrade-Silva, W. A. S. Aleixo, R. J. Cintra
This work introduces low-complexity, multiplierless approximations for the 32-point discrete Fourier transform. The proposed methods are obtained by minimizing the Frobenius error…
Fast Data-independent KLT Approximations Based on Integer Functions
A. P. Radünz, D. F. G. Coelho, F. M. Bayer +2
The Karhunen-Loève transform (KLT) stands as a well-established discrete transform, demonstrating optimal characteristics in data decorrelation and dimensionality reduction. Its ab…
An Approximation for the 32-point Discrete Fourier Transform
R. J. Cintra
This brief note aims at condensing some results on the 32-point approximate DFT and discussing its arithmetic complexity.
Discrete Fourier Transform Approximations Based on the Cooley-Tukey Radix-2 Algorithm
D. F. G. Coelho, R. J. Cintra
This report elaborates on approximations for the discrete Fourier transform by means of replacing the exact Cooley-Tukey algorithm twiddle-factors by low-complexity integers, such…
DCT Approximations Based on Chen's Factorization
C. J. Tablada, T. L. T. da Silveira, R. J. Cintra +1
In this paper, two 8-point multiplication-free DCT approximations based on the Chen's factorization are proposed and their fast algorithms are also derived. Both transformations ar…
Fast Radix-32 Approximate DFTs for 1024-Beam Digital RF Beamforming
A. Madanayake, R. J. Cintra, N. Akram +6
The discrete Fourier transform (DFT) is widely employed for multi-beam digital beamforming. The DFT can be efficiently implemented through the use of fast Fourier transform (FFT) a…
Towards a Low-SWaP 1024-beam Digital Array: A 32-beam Sub-system at 5.8 GHz
Arjuna Madanayake, Viduneth Ariyarathna, Suresh Madishetty +8
Millimeter wave communications require multibeam beamforming in order to utilize wireless channels that suffer from obstructions, path loss, and multi-path effects. Digital multibe…
Radix-2 Self-Recursive Sparse Factorizations of Delay Vandermonde Matrices for Wideband Multi-Beam Antenna Arrays
S. M. Perera, A. Madanayake, R. J. Cintra
This paper presents a self-contained factorization for the Vandermonde matrices associated with true-time delay based wideband analog multi-beam beamforming using antenna arrays. T…
Efficient and Self-Recursive Delay Vandermonde Algorithm for Multi-Beam Antenna Arrays
S. M. Perera, A. Madanayake, R. J. Cintra
This paper presents a self-contained factorization for the delay Vandermonde matrix (DVM), which is the super class of the discrete Fourier transform, using sparse and companion ma…
Low-complexity Three-dimensional Discrete Hartley Transform Approximations for Medical Image Compression
V. A. Coutinho, F. M. Bayer, R. J. Cintra
The discrete Hartley transform (DHT) is a useful tool for medical image coding. The three-dimensional DHT (3D DHT) can be employed to compress medical image data, such as magnetic…
Low-complexity Scaling Methods for DCT-II Approximations
D. F. G. Coelho, R. J. Cintra, A. Madanayake +1
This paper introduces a collection of scaling methods for generating -point DCT-II approximations based on -point low-complexity transformations. Such scaling is based on th…
Low-complexity Architecture for AR(1) Inference
A. Borges, R. J. Cintra, D. F. G. Coelho +1
In this Letter, we propose a low-complexity estimator for the correlation coefficient based on the signed process. The introduced approximation is suitable f…
Rounded Hartley Transform: A Quasi-involution
R. J. Cintra, H. M. de Oliveira, C. O. Cintra
A new multiplication-free transform derived from DHT is introduced: the RHT. Investigations on the properties of the RHT led us to the concept of weak-inversion. Using new construc…
An Integer Approximation Method for Discrete Sinusoidal Transforms
R. J. Cintra
Approximate methods have been considered as a means to the evaluation of discrete transforms. In this work, we propose and analyze a class of integer transforms for the discrete Fo…
A Multiparametric Class of Low-complexity Transforms for Image and Video Coding
D. R. Canterle, T. L. T. da Silveira, F. M. Bayer +1
Discrete transforms play an important role in many signal processing applications, and low-complexity alternatives for classical transforms became popular in recent years. Particul…
Multidimensional Wavelets for Scalable Image Decomposition: Orbital Wavelets
H. M. de Oliveira, V. V. Vermehren, R. J. Cintra
Wavelets are closely related to the Schrödinger's wave functions and the interpretation of Born. Similarly to the appearance of atomic orbital, it is proposed to combine anti-symme…