Unlike traditional phased-array-radar, multiple-input multiple-output (MIMO) radar is capable of achieving more degrees-of-freedom (DOF) and larger virtual aperture (VA) for the direction-of-arrival (DOA) estimation. In this letter, a new universal antenna array approach employing one-level transmitter (Tx) generalized receiver (Rx) presented MIMO to enhance DOA estimation performance. The proposed configuration significantly improves DOF capacity expands VA by utilizing difference co-array...

This letter proposes a new sensor array geometry for the multiple-input multiple-output (MIMO) radar with enhanced degrees of freedom (DOFs) to improve direction-of-arrival (DOA) estimation performance. The configuration utilizes sum coarray difference (SCDC) method achieve increased DOFs, which subsequently provides wider virtual aperture (VAA). produces resultant hole-free uniform linear (ULA) by effectively increasing inter-sensor spacing transmitter. nested-coprime displaced subarrays...

Linear minimum mean-square error (MMSE) detection achieves near-optimal performance in large-scale multiple-input multiple-output (LS-MIMO) systems but entails high computational complexity due to large matrix inversion operations. In this Letter, a novel computationally efficient algorithm based on second-order Richardson method is proposed solve the LS-MIMO problem. While no priori information for first iteration of available, conjugate gradient scheme exploited that greatly reduces number...

Abstract Large‐scale multiple‐input multiple‐output (LS‐MIMO) is one of the promising technologies beyond 5G cellular system in which large antenna arrays at base station (BS) improve capacity and energy‐efficiency. However, number antennas BS makes it challenging to design low‐complexity high‐performance data detectors. Thus, a iterative detection methods, such as Gauss–Seidel conjugate gradient, are introduced achieve complexity‐performance tradeoff. their performance deteriorates for...

In this manuscript, we propose a joint channel and power assignment algorithm for an unmanned aerial vehicle (UAV) swarm communication system based on multi-agent deep reinforcement learning (DRL). Regarded as agent, each UAV to (U2U) link can choose the optimal according current situation after training is successfully completed. Further, mixing network introduced DRL, where Q values of every single agent are non-linearly mapped, call it QMIX algorithm. As accesses state information, learn...

Directional ultrasonic microphones have been used for decades to locate surface partial discharge and corona sites in high voltage equipment. However, there was always some uncertainty of exactly where the were due reflections field view detector. In addition, scanning a complete winding took time. Recently, significant advance this technology achieved with commercial development an acoustic “camera” that can show sound is occurring respect normal visible-light image test object. That is,...

In contrast to uniform linear arrays (ULAs), sparse received considerable attention as they offer wider array aperture and increased degrees of freedom (DoFs). These factors play a vital role in improving the performance direction-of-arrival (DoA) estimation system. However, most existing designs are specific terms configuration. Motivated by this fact, we introduce generalized multicascaded subarrays configuration (GMC-SC). The proposed GMC-SC system cascades series identical following an...

Due to inherent flaws in the mechanism, cooperative spectrum sensing (CSS) often faces two forms of data falsification (SSDF) attacks, independent or collaborative. However, it is inevitable that types attacks will mix together practice. In this paper, we define as mixed attack and propose a Bayesian inference based trust model without users' prior knowledge. A logarithmic function also introduced normalize values. Simulations have shown compared with existing schemes, method can effectively...

A three-stage padding configuration providing a larger continuous virtual aperture and achieving more degrees-of-freedom (DOFs) for the direction-of-arrival (DOA) estimation is presented. The improvement realized by appropriately cascading three-stages of an identical inter-element spacing. Each stage advantageously exhibits array, which subsequently produces hole-free resulting uniform linear array. geometrical approach remains applicable any existing sparse array structures with coarray,...

In this paper, we extend the results obtained by Ezearn on annihilated points for his higher-order nonexpansive mappings to context of general mappings. Precisely in thesis, introduced concept points, which extends notion fixed and it is only meaningful gave some mild conditions when could exist strictly convex Banach spaces. last direction, also Ezearn’s result approximate point sequence

In cognitive radio networks (CRN), spectrum sensing data falsification (SSDF) attack and imperfect reporting channel (RC) are two important factors that affect performance. practical scenarios, attacks may involve both independent collaborative forms, as well channels cooperative in a changing form. this paper, we propose the concept of "mixed attack" RC model subject to Rician distribution analyze its impact on overall performance network system. end, conduct simulations validate these analyses.

Non-uniform linear array (NULA) configurations are well renowned due to their structural ability for providing increased degrees of freedom (DOF) and wider aperture than uniform arrays (ULAs). These characteristics play a significant role in improving the direction-of-arrival (DOA) estimation accuracy. However, most existing NULA geometries primarily applicable circular sources (CSs), while they limitedly improve DOF continuous virtual non-circular (NCSs). Toward this purpose, we present...