Waveform Design for 5G and beyond Systems

5G traffic has very diverse requirements with respect to data rate, delay, and reliability. The concept of using multiple OFDM numerologies adopted in the 5G NR standard will likely meet these multiple requirements to some extent. However, the traffic is radically accruing different characteristics and requirements when compared with the initial stage of 5G, which focused mainly on high-speed multimedia data applications. For instance, applications such as vehicular communications and robotics control require a highly reliable and ultra-low delay. In addition, various emerging M2M applications have sparse traffic with a small amount of data to be delivered. The state-of-the-art OFDM technique has some limitations when addressing the aforementioned requirements at the same time. Meanwhile, numerous waveform alternatives, such as FBMC, GFDM, and UFMC, have been explored. They also have their own pros and cons due to their intrinsic waveform properties. Hence, it is the opportune moment to come up with modification/variations/combinations to the aforementioned techniques or a new waveform design for 5G systems and beyond. The aim of this Special Issue is to provide the latest research and advances in the field of waveform design for 5G systems and beyond

NASA Tech Briefs, May 1994

Topics covered include: Robotics/Automation; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

Resourse Allocation in the Wireless Internet-of-Things

The Internet-of-Things (IoT) is widely regarded as a promising paradigm, marking a revolutionary shift in the way that technology interacts with the world. Despite the rising popularity and extensive integration of IoT across diverse domains, the development and deployment of these interconnected systems are met with considerable challenges. One notable challenge is the scarcity of spectrum resources, which poses a significant obstacle in accommodating the massive data transmission. In addition, small-sized mobile terminals are constrained by limited computation and energy resources. These limitations make the traditional standalone operation of devices increasingly unfeasible. In this thesis, we delve into comprehensive task offloading and resource allocation strategies to utilize of limited resources in wireless IoT. In the first part, we propose a full-dimensional task offloading scheme in the multi-layer computing network. On this basis, we formulate an mixed-integer nonlinear programming (MINLP) problem and develop an inverse reinforcement learning (IRL) based algorithm to solve this problem. Without sacrificing the global optimality, the algorithm can significantly accelerate the optimal branch-and-bound (B&B) algorithm. In the second part, we delve into strategies to optimize energy efficiency within the downlink cell-free massive MIMO systems. We develop a green energy scheme and formulate it as a non-convex MINLP problem. To solve this problem, we propose a novel optimization-embedded deep reinforcement learning (DRL) algorithm, which enjoys the benefits of directly inferring solutions for the formulated problem. In the last part, we develop a NOMA-based task offloading scheme in a multi-layer computing network. On this basis, we formulate the task offloading scheme as a non-convex mixed-integer optimization problem and propose a reincarnating DRL algorithm, where accumulated apriori information is incorporated for fast retraining

The deep space network

The objectives, functions, and organization of the Deep Space Network are summarized along with deep space station, ground communication, and network operations control capabilities. Mission support of ongoing planetary/interplanetary flight projects is discussed with emphasis on Viking orbiter radio frequency compatibility tests, the Pioneer Venus orbiter mission, and Helios-1 mission status and operations. Progress is also reported in tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations

NASA Tech Briefs, September 1992

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Voyager spacecraft system. Volume B - Alternate designs considered for flight spacecraft and hardware subsystems Final technical report

Alternate mission objectives, design characteristics, and system and subsystem designs for Voyager spacecraft syste

Report on active and planned spacecraft and experiments

Information concerning active and planned spacecraft and experiments is reported. The information includes a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represent the efforts and funding of individual countries as well as cooperative arrangements among different countries

1995 BRAC Commission

1995 Hearings (Misc) - April 10-May 10, 1995. Box 93, L-015