scispace - formally typeset
Search or ask a question
Topic

Hadamard transform

About: Hadamard transform is a research topic. Over the lifetime, 7262 publications have been published within this topic receiving 94328 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: A variant of Hadamard (HDM) ratio test is devised to exploit the NC property of the primary signals for spectrum sensing, which is named the NC-HDM algorithm, and it is shown that it is superior to the state-of-the-art algorithms in detection accuracy and/or robustness.
Abstract: Although noncircular (NC) signals are frequently encountered in wireless communications, their statistical property has not yet been utilized in state-of-the-art methods for spectrum sensing. In this paper, a variant of Hadamard (HDM) ratio test is devised to exploit the NC property of the primary signals for spectrum sensing, which is named the NC-HDM algorithm. As the NC-HDM approach is able to exploit full statistical property of the NC signals and handle deviations from independent and identically distributed (IID) noise, it is superior to the state-of-the-art algorithms in detection accuracy and/or robustness. Moreover, performance analysis is conducted for the NC-HDM approach, including the invariant property, false-alarm probability and detection probability. That is, employing the moment-matching Box's Chi-square approximation, the false-alarm probability can be determined. Since the exact moments of the NC-HDM test statistic under the signal-absence hypothesis can be determined and all moments have been matched, the derived false-alarm probability is very accurate, leading to simple and precise computation of the theoretical decision threshold. On the other hand, as the first two exact moments of the NC-HDM test statistic under the signal-presence hypothesis can be precisely calculated, the detection probability based on moment-matching Beta approximation is quite accurate. Numerical results are included to demonstrate the superiority of the NC-HDM approach and validate our theoretical calculations.

35 citations

Journal ArticleDOI
15 May 2014
TL;DR: In this article, the Tikhonov regularization was combined with the theory of reproducing kernels to give natural generalized solutions of Hadamard and tensor products equations for matrices.
Abstract: We shall give natural generalized solutions of Hadamard and tensor products equations for matrices by the concept of the Tikhonov regularization combined with the theory of reproducing kernels.

35 citations

Journal ArticleDOI
TL;DR: A Unified fast algorithm for computation of the introduced tree-structured Haar transforms is presented, which requires 2(N − 1) additions and 3N −2 multiplications.
Abstract: The Haar transform is generalized to the case of an arbitrary time and scale splitting. To any binary tree we associate an orthogonal system of Haar-type functions – tree-structured Haar (TSH) functions. Unified fast algorithm for computation of the introduced tree-structured Haar transforms is presented. It requires 2(N − 1) additions and 3N −2 multiplications, where N is transform order or, equivalently, the number of leaves of the binary tree.

35 citations

Journal ArticleDOI
TL;DR: In this article, the Hermite-Hadamard type inequalities for generalized convex functions were established for Tcheby-chev systems, based on moment spaces induced by Tchebyschev systems.
Abstract: Applying some fundamental results concerning moment spaces induced by Tcheby-chev systems, we establish Hermite–Hadamard type inequalities for generalized convex functions.

35 citations

Journal ArticleDOI
TL;DR: In this article, an integral identity and some Hermite-Hadamard-Fejer type integral inequalities for p-convex functions in fractional integral forms are obtained.
Abstract: In this paper, firstly, Hermite–Hadamard–Fejer type inequalities for p-convex functions in fractional integral forms are built. Secondly, an integral identity and some Hermite–Hadamard–Fejer type integral inequalities for p-convex functions in fractional integral forms are obtained. Finally, some Hermite–Hadamard and Hermite–Hadamard–Fejer inequalities for convex, harmonically convex and p-convex functions are given. Many results presented here for p-convex functions provide extensions of others given in earlier works for convex, harmonically convex and p-convex functions.

34 citations


Network Information
Related Topics (5)
Bounded function
77.2K papers, 1.3M citations
85% related
Matrix (mathematics)
105.5K papers, 1.9M citations
85% related
Differential equation
88K papers, 2M citations
85% related
Iterative method
48.8K papers, 1.2M citations
85% related
Upper and lower bounds
56.9K papers, 1.1M citations
84% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023339
2022850
2021391
2020444
2019427
2018372