Owing to its distinctive merits, non-orthogonal multiple access (NOMA) techniques have been utilized in unmanned aerial vehicle (UAV) enabled wireless base stations provide effective coverage for terrestrial users. However, the security of NOMA-UAV systems remains a challenge due line-of-sight air-to-ground channels and higher transmission power weaker users NOMA. In this paper, we propose two schemes guarantee secure UAV-NOMA networks. When only one user requires transmission, derive...

Non-orthogonal multiple access (NOMA) has been developed as a key multi-access technique for 5G. However, secure transmission remains challenge in NOMA. Especially, the user with weakest channel is most threatened by eavesdropping, due to its highest transmit power. Two schemes are proposed generate artificial jamming at NOMA base station (BS), aiming disrupting potential eavesdropping without affecting legitimate transmission. In first scheme, power of maximized, received each receiver...

Gaussian/non-Gaussian impulsive noises in underwater acoustic (UWA) channel seriously impact the quality of communication. The common denoising algorithms are based on Gaussian noise model and difficult to apply coexistence noises. Therefore, a new UWA is described this paper by combining symmetric α-stable (SαS) distribution normal distribution. Furthermore, novel signal algorithm called AWMF+GDES proposed. First, non-Gaussian adaptively suppressed adaptive window median filter (AWMF)....

It is a huge challenge for the receiver to correctly identify modulation types due complex underwater channel environment and severe noise interference. Additionally, real-time communications have strict requirements in terms of time. In order solve this well-known issue, work, we combine automatic feature extraction learning ability recurrent neural network (RNN) convolutional (CNN) designing recognition model acoustic signals. The proposed based on deep hybrid networks called (R&CNN). As...

Molybdenum disulfide (MoS2), a two-dimensional transition metal (TMD), is of great concern in microwave absorption (MA). Nevertheless, pure MoS2 has limitations realizing outstanding MA performance owing to its lower conductivity and smaller dielectric constant. To address this, compounding it with highly conductive CuS not only improves impedance-matching properties but also increases the interfacial polarization within material enhances material. In this study, flower-like heterostructured...

While fine-tuned large language models (LLMs) excel in generating grammatically valid SQL Text-to-SQL parsing, they often struggle to ensure semantic accuracy queries, leading user confusion and diminished system usability. To tackle this challenge, we introduce SQLFixAgent, a new consistency-enhanced multi-agent collaborative framework designed for detecting repairing erroneous SQL. Our comprises core agent, SQLRefiner, alongside two auxiliary agents: SQLReviewer QueryCrafter. The agent...

Ferroelectricity in calcium doped hafnium oxide (Ca:HfO2) thin films has been experimentally proved for the first time this work. All prepared by chemical solution deposition exhibited smooth and crack-free surfaces, which were observed using an atomic force microscope. After 104 field cycling, a maximum remanent polarization of 10.5 μC/cm2 was achieved HfO2 with 4.8 mol. % Ca content. Meanwhile, breakdown film occurred after 7 × 106 electric cycles. A phase transition from monoclinic to...

An underwater wireless optical communication (UWOC) system with a 450-nm laser diode and 150-MHz PIN photodiode is presented. The 16-ary quadrature amplitude modulation scheme employed realized on field-programmable gate array (FPGA) to efficiently provide high data rate. Experimental results show that this can achieve rates up 50 Mbps over distance of 3 m bit error rate (BER) 7.11×10-4 in artificial seawater at 35‰ salinity, where the attenuation coefficient 0.481. This BER below forward...

Non-orthogonal multiple access (NOMA) aided unmanned aerial vehicle (UAV) is becoming a promising technique for future wireless networks. However, its security remains great challenge due to the line-of-sight in UAV communications and high transmit power weak users NOMA. Thus, this paper, we propose allocation (PA) scheme NOMA-UAV networks with circular trajectory, maximize sum rate of common while guaranteeing specific user. To achieve this, consider three cases based on distance from...

Underwater wireless sensor network (UWSN) plays a vital role in the field of ocean development and exploration. Designing routing protocol for UWSN is great challenge due to characteristics short lifetime high delay. This paper proposes Q-learning based optimization algorithm UWSN. Two reward functions are designed on average residual energy network, integrating factors such as information, transmission delay link success rate better balance quality lifetime. In addition, holding time...

With the increasingly mature sensor technology and increasing popularity of broadband network, "the Internet-of-Everything" era is coming, mobile Internet Things (IoT) booming around world. However, IoT communication networks face serious challenges, which are caused by complex variable environments. The applications can produce large-scale data, will consume substantial energy. transmit antenna selection (TAS) cooperative schemes commonly used to reduce complexity energy consumption,...

Automatic modulation recognition (AMR) technology enables receivers to automatically recognize the type of received signal for correct demodulation data, but there are still many shortcomings be addressed. To achieve accurate and efficient AMR, this paper proposes a data augmentation method which can increase amount by seven times solve problem small sample size more effectively than existing methods. In addition, concept microscale, rationalizes underwater acoustic into time series,...