PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Energy-efficient design for mmWave-enabled NOMA-UAV networks

Energy-efficient design for mmWave-enabled NOMA-UAV networks
2021-03-16
(Press-News.org) Non-orthogonal multiple access (NOMA) and millimeter-wave (mmWave) are two crucial techniques of 5G to meet the explosive capacity demands. On the other hand, UAVs deployed as aerial base stations are potential to provide ubiquitous coverage and satisfy users' multifarious requirements due to their flexibility and mobility. Nevertheless, the finite onboard energy is a fundamental limit of UAVs, which can deter the performance of UAV communication networks. Therefore, the researchers Xiaowei PANG and Nan ZHAO from Dalian University of Technology, Jie TANG and Xiuyin ZHANG from South China University of Technology, and Yi QIAN from University of Nebraska-Lincoln have focused on designing energy-efficient transmission schemes for mmWave-enabled NOMA-UAV networks. The network model is illustrated in Fig. 1, where the UAV equipped with multiple antennas serves K single-antenna ground users who are grouped into M clusters in the downlink.

"Although a large amount of research has contributed to integrating mmWave or NOMA with UAV communications, respectively," the five researchers wrote, "few of them investigated on mmWave-enabled NOMA-UAV networks."

In mmWave networks, the number of supported users conventionally cannot be larger than the number of RF chains at the same time-frequency resources. To break this fundamental limit, users are grouped into multiple clusters according to their channel correlations, and NOMA is employed in each cluster to serve the users simultaneously. To achieve a good balance between system complexity and performance, a hybrid precoding architecture is adopted to reduce the hardware cost and energy consumption. The authors aim to maximize the energy efficiency of mmWave-enabled NOMA-UAV networks by optimizing the UAV placement, hybrid precoding and power allocation. Due to the fact that the overall energy efficiency maximization problem is intractable, it is divided into several sub-problems. First, they optimize the UAV placement considering the total channel strength of all UAV-served users. And then, the hybrid precoding schemes with user clustering are proposed to better reap the multi-antenna gain. The last step is to optimize the power allocation among users to maximize the energy efficiency with users' quality of service requirements and an efficient algorithm is presented to solve the problem iteratively.

It's worth mentioning that three hybrid precoding schemes are introduced in the network, all of which perform user clustering and design the analog and digital precoding to improve the multiplexing gains and suppress the inter-user interference. Particularly, the major distinction among them is that they can achieve different performance of user fairness, spectrum efficiency and energy efficiency, which are further demonstrated by simulation results. The effectiveness of the proposed energy-efficient design is verified through numerical comparisons with other schemes without UAV placement optimization and without energy efficiency requirement. Moreover, numerical results also reveal the effects of the maximum UAV transmit power and the number of RF chains on the energy efficiency.

INFORMATION:

For more details, please refer to the upcoming paper "Energy-efficient design for mmWave -enabled NOMA-UAV networks", to be published in SCIENCE CHINA Information Sciences, 2021, 64(4): 140303.

https://link.springer.com/article/10.1007/s11432-020-2985-8


[Attachments] See images for this press release:
Energy-efficient design for mmWave-enabled NOMA-UAV networks

ELSE PRESS RELEASES FROM THIS DATE:

SwRI researcher theorizes worlds with underground oceans support, conceal life

SwRI researcher theorizes worlds with underground oceans support, conceal life
2021-03-16
SAN ANTONIO -- March 16, 2021 -- One of the most profound discoveries in planetary science over the past 25 years is that worlds with oceans beneath layers of rock and ice are common in our solar system. Such worlds include the icy satellites of the giant planets, like Europa, Titan and Enceladus, and distant planets like Pluto. In a report presented at the 52nd annual Lunar and Planetary Science Conference (LPSC 52) this week, Southwest Research Institute planetary scientist S. Alan Stern writes that the prevalence of interior water ocean worlds (IWOWs) in our solar system suggests they may be prevalent in other star systems as well, vastly expanding the conditions for planetary habitability and biological survival over time. It has been known for many years that worlds like Earth, ...

At face value: Using facial analysis algorithm to track changes due to Parkinson's disease

At face value: Using facial analysis algorithm to track changes due to Parkinsons disease
2021-03-16
Parkinson's disease (PD) is a well-studied neurodegenerative disorder that affects between 7 and 10 million people worldwide. Despite PD being a recurrent topic in the medical literature for over 200 years, its mechanisms are largely unclear, and existing treatments are aimed at improving the patient's symptoms. Among PD's most common symptoms are motor problems, including as tremors, slowness, and muscular rigidity. These, combined with many non-motor symptoms, cause many PD patients to develop facial abnormalities, such as face skin problems and difficulties making facial expressions. Such problems are not to be taken lightly, as one's face plays a crucial ...

Spontaneous superconducting currents in Sr2RuO4

Spontaneous superconducting currents in Sr2RuO4
2021-03-16
Superconductivity is a complete loss of electrical resistance. Superconductors are not merely very good metals: it is a fundamentally different electronic state. In normal metals, electrons move individually, and they collide with defects and vibrations in the lattice. In superconductors, electrons are bound together by an attractive force, which allows them to move together in a correlated way and avoid defects. In a very small number of known superconductors, the onset of superconductivity causes spontaneous electrical currents to flow. These currents ...

Acoustic graphene plasmons study paves way for optoelectronic applications

Acoustic graphene plasmons study paves way for optoelectronic applications
2021-03-16
KAIST researchers and their collaborators at home and abroad have successfully demonstrated a new methodology for direct near-field optical imaging of acoustic graphene plasmon fields. This strategy will provide a breakthrough for the practical applications of acoustic graphene plasmon platforms in next-generation, high-performance, graphene-based optoelectronic devices with enhanced light-matter interactions and lower propagation loss. It was recently demonstrated that 'graphene plasmons' - collective oscillations of free electrons in graphene coupled to electromagnetic waves of light - can be used to trap and compress optical waves inside a very thin dielectric ...

Deforestation taking a heavy toll on international bird haven

Deforestation taking a heavy toll on international bird haven
2021-03-16
An analysis has found deforestation is severely affecting forest bird species in Colombia, home to the greatest number of bird species in the world. University of Queensland-led research, steered by Dr Pablo Negret, analysed the impact of deforestation on 550 bird species, including 69 only found in the South American nation. "Our study has shown an astonishing reduction in bird species habitat," Dr Negret said. "One third of the forest bird species in Colombia have lost at least a third of their historical habitat, and that's just using the most recent data we have available - from 2015. "Moreover, 18 per cent or 99 species have lost more than half of their historical habitat to date. "By 2040, we expect this will increase to 38 per cent or 209 species. "Sadly, many of those ...

NTU Singapore scientists develop device to 'communicate' with plants using electrical signals

2021-03-16
A team of scientists led by Nanyang Technological University, Singapore (NTU Singapore) has developed a device that can deliver electrical signals to and from plants, opening the door to new technologies that make use of plants. The NTU team developed their plant 'communication' device by attaching a conformable electrode (a piece of conductive material) on the surface of a Venus flytrap plant using a soft and sticky adhesive known as hydrogel. With the electrode attached to the surface of the flytrap, researchers can achieve two things: pick up electrical signals to monitor how the plant responds to ...

A new type of recyclable: Finding new uses for established drugs

A new type of recyclable: Finding new uses for established drugs
2021-03-16
Researchers from Tokyo Medical and Dental University (TMDU) uncover potential novel therapeutic strategies for oral and esophageal carcinomas Tokyo, Japan - Discovering and treating tumors before they spread throughout the body is key for cancer patients to achieve positive outcomes. When tumor cells spread, which is known as metastasis, they can take over other organs and lead to death. Oral and esophageal carcinomas, or mouth and throat cancers, frequently metastasize to the lymph nodes. Unfortunately, there are currently no therapies that are specific to treating these particular cancers. Now, researchers at Tokyo Medical and Dental University (TMDU) identified several drugs ...

Quadruple fusion imaging via transparent ultrasound transducer

Quadruple fusion imaging via transparent ultrasound transducer
2021-03-16
A quadruple fusion optical and ultrasound imaging system has been developed that allows diagnosis of eye conditions or tumors or to see the environment inside the body using a transparent ultrasound transducer. Professor Chulhong Kim of POSTECH's Department of Electrical Engineering, Convergence IT Engineering, and Mechanical Engineering, Dr. Byullee Park of Department of Convergence IT Engineering, Ph.D. candidate Jeongwoo Park of School of Interdisciplinary Bioscience and Bioengineering, Professor Hyung Ham Kim of Department of Convergence IT Engineering, and Professor Unyong Jeong of Department of Materials ...

Flat brain organoids grown on 3D-printed scaffolds show intrinsic gyrification

2021-03-16
The research, by an international team from the Autonomous University of Madrid and the Technical University of Denmark, used 3D printing to create scaffolds for engineered flat brain organoids. The scaffolds allowed the brain organoid size to be significantly increased and after 20 days, self-generated folding was observed. END ...

Militarization negatively influences green growth

Militarization negatively influences green growth
2021-03-16
Military expenditures are highly counterproductive to green economic growth- documented by a recent study conducted by UrFU economist collaboration with an international research team. Sustainable economic development or green growth requires cleaner energy and green technology that can mitigate the negative externalities (e.g., carbon emission) of economic growth. The study utilized various macroeconomic indicators for 21 OECD countries over the year 1980-2016. This empirical study focusing on the dynamic impact of innovation, militarization and renewable energy on the green economy is published in the journal "Environmental Science and Pollution Research". On the one hand, the military-industry (land vehicles, aircraft, and sea-vessels) consume a gargantuan ...

LAST 30 PRESS RELEASES:

Corpse flowers are threatened by spotty recordkeeping

Riding the AI wave toward rapid, precise ocean simulations

Are lifetimes of big appliances really shrinking?

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

[Press-News.org] Energy-efficient design for mmWave-enabled NOMA-UAV networks