88 research outputs found

    USAGE OF 5G IN UAV MISSIONS FOR ISR

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    Traditionally, UAVs operate on a one-to-one transmission mode where the UAVs have one data link between one ground command and control station. Therefore, the radius at which the UAV can travel is limited. The bandwidth of the traditional link is limited to less than 8Mbps and the quality of the video is below 1080p. 4G technology has been applied to the UAV data link to solve some of these more traditional problems. However, the 4G data link also comes with its own limitations such as downlink interference and can only be useful in scenarios with a high delay tolerance. 5G technology solves the spatial coverage problem by increasing the number of antenna modules and fusing the antenna module and radio hardware. The result is a three-dimensional beam. The UAV itself can be used as a base station for the 5G network, so that all ground stations can be connected as the UAV continues its flight path. UAVs can also be used as aerial nodes in a larger swarm network to offer coverage over larger areas. Additionally, the use of the OpenStack architecture can allow the Navy to customize protocols as desired. The proposed research includes investigating how current UAV to ship/shore communications are conducted. The objective of this thesis is to determine if 5G communications are possible between UAV and ship/shore assets, to successfully connect a UAV to the 4G and possibly 5G network and to determine if UAVs can send data between each other to the ground station.Lieutenant Commander, United States NavyApproved for public release. Distribution is unlimited

    Securing NextG networks with physical-layer key generation: A survey

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    As the development of next-generation (NextG) communication networks continues, tremendous devices are accessing the network and the amount of information is exploding. However, with the increase of sensitive data that requires confidentiality to be transmitted and stored in the network, wireless network security risks are further amplified. Physical-layer key generation (PKG) has received extensive attention in security research due to its solid information-theoretic security proof, ease of implementation, and low cost. Nevertheless, the applications of PKG in the NextG networks are still in the preliminary exploration stage. Therefore, we survey existing research and discuss (1) the performance advantages of PKG compared to cryptography schemes, (2) the principles and processes of PKG, as well as research progresses in previous network environments, and (3) new application scenarios and development potential for PKG in NextG communication networks, particularly analyzing the effect and prospects of PKG in massive multiple-input multiple-output (MIMO), reconfigurable intelligent surfaces (RISs), artificial intelligence (AI) enabled networks, integrated space-air-ground network, and quantum communication. Moreover, we summarize open issues and provide new insights into the development trends of PKG in NextG networks

    Effect of Exponential Correlation Model on Spectral and Energy Efficiency for Massive MIMO Systems

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    During the past few years, the number of wireless devices has been increasing rapidly. Wireless networks are serving and connecting billions of wireless devices where these devices are demanding higher data rate and lower latency to be able to support voice, video and gaming applications. Moreover, the consumed energy by the wireless systems will be increasing. Hence, the Fifth generation (5G) wireless networks needs to provide higher data rate, serve larger number of users simultaneously and be more energy efficient. One of the promising technologies that can meet the above requirements is Massive Multiple Input Multiple Output (MIMO). The main concept of this technology is to equip the base station with hundreds of antennas and serve tens of users simultaneously. The amount of research on massive MIMO increases rapidly, but there is little attention so far on the spatial correlation between the channels. Most of the published work are assuming that the antennas are uncorrelated which is not the case in real-world situations. In this dissertation, the effect of channel correlation model on the Massive MIMO performance is investigated. First, the exponential correlation model is applied to the Massive MIMO system model. We used a pilot based linear minimum mean square error (LMMSE) channel estimator for the uplink data transmission. The impact of the channel correlation on the channel estimation accuracy is investigated. Due to having channel reciprocity, the channel state information will be the same for uplink and downlink data transmission. It is assumed that there is block fading where there are static channels. It is shown that the channel estimation is more accurate with higher SNR values. Second, the uplink and downlink spectral efficiency of the LMMSE estimators are investigated where spatial correlation models are applied to the system to generate the channel covariance matrix. The lower capacity of the uplink and downlink data transmissions are derived to see the effect of applying exponential correlation model. We study the lower capacity bound based on imperfect knowledge of the channel. In the first part, we are considering a one cell system model with one base station that is equipped with N antennas and serving single antenna user. In the second part, a Massive MIMO system of a single cell is considered. The system model is having a base station with multiple antennas that is serving user terminals equipped with multiple antennas. It is proved that the spectral efficiency is improved by increasing the number of base station antennas which shows the scalability of Massive MIMO systems. Finally, the transmit power of Massive MIMO system is defined as the consumed energy by the amplifier divided by coherence time while energy efficiency of Massive MIMO system can be expressed as the ratio between the spectral efficiency and the emitted power. The influence of the channel spatial correlation on the energy efficiency is investigated where it is noticed that there is higher energy efficiency with higher number of base station antenna
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