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In this paper, we propose a novel polar code construction scheme, suitable for the underwater acoustic (UWA) multi-user communication system using orthogonal frequency division multiplexing (OFDM). We use codes because rate of can be arbitrarily designed. Moreover, also used to create nested structure, divided into several subsets (codebook). exploit feature and place information bits in codebook avoid superimposition all users. This helps eliminate influence power allocation coefficient...

In this paper, we propose a blind side information detection scheme for partial transmitted sequence (PTS) peak-to-average power ratio reduction (PAPR) method in underwater acoustic (UWA) orthogonal frequency division multiplexing (OFDM) communication systems. The proposed employs corresponding table between the distributions of pilot tones and phase rotation candidates to obtain pseudo-optimum PTS PAPR performance dramatic total calculation cost. Meanwhile, predefined are used identify...

In recent decades, imaging sonar has been the most widely employed remote sensing instruments in field of underwater detection. The multibeam echo sounder (MBES) plays an important role obtaining high-accuracy seabed topography. However, resolution MBES substantially decreases with increasing distance. Synthetic aperture (SAS) achieves constant on along-track, improving fineness image. conventional side-scan SAS usually only 2D images, and gaps always exist. this modeling experimental...

Existing GAN inversion methods work brilliantly for high-quality image reconstruction and editing while struggling with finding the corresponding images low-quality inputs. Therefore, recent works are directed toward leveraging supervision of paired inversion. However, these infeasible in real-world scenarios further hinder performance improvement. In this paper, we resolve problem by introducing Unsupervised Domain Adaptation (UDA) into Inversion process, namely UDA-Inversion, both editing....

The detection accuracy of the multibeam echo sounder (MBES) can be damaged severely and inevitably due to mismachining tolerance transducer array. Therefore, it is necessary demonstrate performance multi-element array guarantee processing algorithms. In this paper, a kind MBES receiving self-calibrating method proposed manage serious defocusing problem conventional methods. We analyze error source their effect on detection. near-field beamforming least residual criterion methods are employed...

Abstract A radio-frequency (RF) inductively coupled negative hydrogen ion source (NHIS) has been adopted in the China Fusion Engineering Test Reactor (CFETR) to generate ions. By incorporating level-lumping method into a three-dimensional fluid model, volume production and transportation of H − NHIS, which consists cylindrical driver region rectangular expansion chamber, are investigated self-consistently at large input power (40 kW) different pressures (0.3–2.0 Pa). The results indicate...

High-accuracy level underwater acoustical surveying plays an important role in ocean engineering applications, such as subaqueous tunnel construction, oil and gas exploration, resources prospecting. This novel imaging method is eager to break through the existing theory achieve a higher accuracy of surveying. Multibeam Synthetic Aperture Sonar (MBSAS) kind that can 3D high-resolution detecting overcome disadvantages traditional methods, Echo Sounder (MBES) (SAS). However, resolution...

To overcome the disadvantage of side information transmission, an improved selective mapping algorithm is proposed for peak-to-average power ratio reduction multiple-input multiple-output orthogonal frequency division multiplexing communication via underwater acoustic channels. The scrambling patterns are carried by comb pilot with different distributions. And taking advantage neritic channel sparse characteristics, can be distinguished without information. results experiment performed...

In this paper, the effect of coil structure, as well gas pressure, on spatial distribution an inductively coupled argon plasma is numerically investigated based a self-developed three-dimensional fluid model. The model modified ambipolar diffusion model, in which electron density solved by quasi-neutral condition, ion and neutral particle are obtained solving continuity equations, flux achieved full momentum balance equation. addition, inductive electric field governed Maxwell frequency...

In this paper, we proposed an embedded side information (SI) transmission scheme based on polar code construction for PAPR reduction using the PTS in underwater Acoustic (UWA) Orthogonal Frequency Division Multiplexing (OFDM) communication system. We use codes due to ability of arbitrarily designed rate. Additionally, can be employed establish a nested structure consisting multiple subsets. The SI bits codeword by exploiting these features. Thus, approach does not occupy existing data rates...

A novel Selected-mapping (SLM) Peak-to-average power ratio (PAPR) reduction scheme requires no Side information (SI) in Underwater acoustic (UWA) OFDM system is proposed. In the proposed scheme, every distinct phase sequence represented by a unique Orthogonal comb pilot (OPS), and orthogonal properties of OPSs are used to distinguish index sequences at receiver. Therefore, does not need reserve bits for transmitting SI, so that data rate can be raised. Simulation results show PAPR...

A Bit-Interleaved Code Modulation (BICM) scheme based on the polar codes (Polar-BICM), suitable for underwater acoustic (UWA) communication system utilizing orthogonal frequency division multiplexing (OFDM) is proposed in this paper. In scheme, design and implementation of encoder modulator are combined to improve rate, while traditional schemes usually consider independently. The BER performance affected by variance interleaver types, lengths code carefully discussed LDPC-BICM Trellis Coded...

Flow matching as a paradigm of generative model achieves notable success across various domains. However, existing methods use either multi-round training or knowledge within minibatches, posing challenges in finding favorable coupling strategy for straight trajectories. To address this issue, we propose novel approach, Straighter trajectories Matching (StraightFM). It straightens with the guided by diffusion from entire distribution level. First, to straighten trajectories, creating...