A General Order Reduction Method of Wideband Digital Predistortion Model Using Attention Mechanism

In wireless networks, for the common in-phase and quadrature-phase ( I / Q ) imbalance in the transmitters, the I / Q branch models of digital predistortion (DPD) need to be identified separately, to improve the linearization effects. The existing order reduction methods of the predistorter are based on the contributions of the complex basis function terms, so as not to deal with the different contributions of I / Q components of the complex basis function terms caused by the separate identification of the I / Q branch models. The separate pruning of the I / Q branch models will increase the complexity. Aiming at this issue, this paper proposes a general order reduction method based on the attention mechanism for the predistortion of the power amplifiers (PAs). This method is suitable for pruning both the traditional models and neural network-based models. In this method, the attention mechanism is used to evaluate the contributions of the real basis function terms to the predistorted output’s I / Q components through offline training, and the influence of the cross terms of the I / Q branch models is considered. The experimental results based on the comparison with other typical methods under 100 MHz Doherty PA and different I / Q imbalance levels show that this method has superior pruning performance and good linearization ability.

Approximation of Directional Step Derivative of Complex-Valued Functions Using a Generalized Quaternion System

The step derivative of a complex function can be defined with various methods. The step direction defines a basis that is distinct from that of a complex number; the derivative can then be treated by using Taylor series expansion in this direction. In this study, we define step derivatives based on complex numbers and quaternions that are orthogonal to the complex basis while simultaneously being distinct from it. Considering previous studies, the step derivative defined using quaternions was insufficient for applying the properties of quaternions by setting a quaternion basis distinct from the complex basis or setting the step direction to which only a part of the quaternion basis was applied. Therefore, in this study, we examine the definition of quaternions and define the step derivative in the direction of a generalized quaternion basis including a complex basis. We find that the step derivative based on the definition of a quaternion has a relative error in some domains; however, it can be used as a substitute derivative in specific domains.

Linguo-Paradigmatic Aspects of the Concept “Tree”

In ancient Georgia, tree was designated as a beam, which is a common Kartvelian linguistic symbol. Tree is often used as a part, forming the complex basis and acquires another metaphorical meaning. Symbolic meaning of three is also very interesting which is met in Christian, as well as pagan world. A trace of worshiping a tree is met in oral telling, fairy tales and native poems and songs, as well as toponyms and the monuments of the objective culture. There are a lot of symbols of tree. Each type expresses different aspects of the sacral tree symbolism. A cult of a tree has a certain place in historical development of the Christian religion. In the Christian perception, an eternity of life is related to a tree. It is a metaphor creating the world. In the ecclesiastic poetry, “A tree of knowledge” and “A life tree”, both consider the Christ. Symbolism of a beam is also interesting. It is connected to the torment of the Savior as well. It is called as “a beam of life”, which underlies the vivifying power of a cross, which spread the blessing grace on the world. Symbolism of the tree yield is also distinguished. It is represented in various ways in the Bible and the Spiritual poetry.

EXPRESS: Understanding the document bias in face matching

Matching unfamiliar faces is a well-studied task, apparently capturing important everyday decisions such as ID checks. In typical lab studies participants make same/different judgements to pairs of faces, presented in isolation and without context. However, it has recently become clear that matching faces embedded in documents (e.g. passports and driving licences) induces a bias, resulting in elevated levels of ‘same person’ responses. While practically important, it remains unclear whether this bias arises due to expectations induced by the ID cards or interference between textual information and faces. Here we observe the same bias when faces are embedded in blank (i.e. non-authoritative) cards carrying basic personal information, but not when the same information is presented alongside a face without the card (Experiments 1 & 2). Cards bearing unreadable text (blurred or in an unfamiliar alphabet) do not induce the bias but those bearing arbitrary (non-biographical) words do (Experiments 3 and 4). The results suggest a complex basis for the effect, relying on multiple factors which happen to converge in photo-ID.

Irreducible first Brillouin zone for two-dimensional magnonic crystals with asymmetric complex lattices

Two-dimensional (2D) magnonic crystal (MC) with an asymmetric complex basis is proposed in this paper, and its band structures are calculated in the whole area of the first Brillouin zone (BZ). This kind of MCs is composed of two different atoms in the unit cell, and the symmetry of the unit cell is broken due to changes in the position of the second atom, so the irreducible part of the BZ is no longer the small area [Formula: see text] for square lattice, and it must be expanded to the whole first BZ. Only by investigating the whole first BZ, can we get the true full band-gap for this kind of MCs.

Complex Pignistic Transformation-Based Evidential Distance for Multisource Information Fusion of Medical Diagnosis in the IoT

Multisource information fusion has received much attention in the past few decades, especially for the smart Internet of Things (IoT). Because of the impacts of devices, the external environment, and communication problems, the collected information may be uncertain, imprecise, or even conflicting. How to handle such kinds of uncertainty is still an open issue. Complex evidence theory (CET) is effective at disposing of uncertainty problems in the multisource information fusion of the IoT. In CET, however, how to measure the distance among complex basis belief assignments (CBBAs) to manage conflict is still an open issue, which is a benefit for improving the performance in the fusion process of the IoT. In this paper, therefore, a complex Pignistic transformation function is first proposed to transform the complex mass function; then, a generalized betting commitment-based distance (BCD) is proposed to measure the difference among CBBAs in CET. The proposed BCD is a generalized model to offer more capacity for measuring the difference among CBBAs. Additionally, other properties of the BCD are analyzed, including the non-negativeness, nondegeneracy, symmetry, and triangle inequality. Besides, a basis algorithm and its weighted extension for multi-attribute decision-making are designed based on the newly defined BCD. Finally, these decision-making algorithms are applied to cope with the medical diagnosis problem under the smart IoT environment to reveal their effectiveness.

The technique development of non-washing of mineral fertilizers in the soil through the screen formed on the interpolymer complex basis

The problem of global climate change is on the agenda of mankind, not only because of the average annual temperature rise on the planet but also because of changes in the entire geosystem, rising global oceans, melting ice and permanent glaciers, increasing uneven rainfall, changing river flow patterns and climate instability, other changes involved. The world pays special attention to research work to develop technologies for the management and efficient use of water resources. In particular, it is important to conduct research to develop new water-saving irrigation technologies using cheap and chemical, and technical means.

SYNTHESIS OF A FILTER BANK BASED ON WEYL-HEISENBERG COMPLEX BASIS

Рассмотрен синтез банка цифровых фильтровдля частотно-временного анализа дискретных комплексных сигналов, заданных на конечном интервале. Для этой цели предлагается использовать специальный инструментарий - комплексный сигнальный базис Вейля-Гейзенберга. Показано, что такой подход позволяет гибко настраивать частотно-временные характеристики цифровых фильтров в соответствии с желаемым эталоном и ведет к многоскоростной многоканальной фильтровой процедуре, допускающей быструю вычислительную реализацию. Получены конечные формулы, описывающие банк фильтров, и приводится анализ его вычислительной эффективности. The synthesis of a bank of digital filters for the frequency-time analysis of complex discrete signals defined on a finite interval is considered. For this purpose, it is proposed to use a special tool -kit - a complex signal basis of Weyl-Heisenberg. It is shown that this approach allows flexible adjustment of the time-frequency characteristics of digital filters in accordance with the desired standard and leads to a multi-speed multi-channel filter procedure that allows fast computational implementation. The final formulas describing the filter bank are obtained, and an analysis of its computational efficiency is presented.