Adaptive Coding and Modulation Aided Mobile Relaying for Millimeter-Wave Flying Ad-Hoc Networks

The emerging drone swarms are capable of carrying out sophisticated tasks in support of demanding Internet-of-Things (IoT) applications by synergistically working together. However, the target area may be out of the coverage of the ground station and it may be impractical to deploy a large number of drones in the target area due to cost, electromagnetic interference and flight-safety regulations. By exploiting the innate \emph{agility} and \emph{mobility} of unmanned aerial vehicles (UAVs), we conceive a mobile relaying-assisted drone swarm network architecture, which is capable of extending the coverage of the ground station and enhancing the effective end-to-end throughput. Explicitly, a swarm of drones forms a data-collecting drone swarm (DCDS) designed for sensing and collecting data with the aid of their mounted cameras and/or sensors, and a powerful relay-UAV (RUAV) acts as a mobile relay for conveying data between the DCDS and a ground station (GS). Given a time period, in order to maximize the data delivered whilst minimizing the delay imposed, we harness an $\epsilon$-multiple objective genetic algorithm ($\epsilon$-MOGA) assisted Pareto-optimization scheme. Our simulation results demonstrate that the proposed mobile relaying is capable of delivering more data. As specific examples investigated in our simulations, our mobile relaying-assisted drone swarm network is capable of delivering $45.38\%$ more data than the benchmark solutions, when a stationary relay is available, and it is capable of delivering $26.86\%$ more data than the benchmark solutions when no stationary relay is available

Physical Layer Security of Spatially Modulated Sparse-Code Multiple Access in Aeronautical Ad-Hoc Networking

For improving the throughput while simultaneously enhancing the security in aeronautical ad-hoc networking (AANET), a channel quality indicator (CQI)-mapped spatially modulated sparse code multiple access (SM-SCMA) scheme is proposed in this paper. On one hand, we exploit the joint benefits of spatial modulation and SCMA for boosting the data rate. On the other hand, a physical-layer secret key is generated by varying the SM-SCMA mapping patterns based on the instantaneous CQI in the desired link. This guarantees the security of AANETs, since this secret key is not exchanged between the source aeroplane and its destination. Due to the line-of-sight (LoS) propagation in the AANET, other aeroplanes or eavesdroppers may detect the signals delivered in the desired link. However, they are unable to translate the detected signals into the original confidential information, even if multiple copies of the signals are recoined over multiple hops of the AANET, because they have no knowledge of the CQI-based SM-SCMA mapping pattern. The performance of the CQI-mapped SM-SCMA is evaluated in terms of both its bit error rate and its ergodic secrecy rate, which substantiates that the proposed scheme secures the confidential information exchange in the multi-hop AANET

Beam Selection Assisted UAV-BS Deployment and Trajectory for Beamspace MmWave Systems

Exploiting unmanned aerial vehicles (UAVs) as base stations (UAV-BS) can enhance capacity, coverage, and energy efficiency of wireless communication networks. To fully realize this potential, millimeter wave (mmWave) technology can be exploited with UAV-BS to form mmWave UAV-BS. The major difficulty of mmWave UAV-BS, however, lies in the limited energy of UAV-BS and the multiuser interference (MUI). Beam division multiple access with orthogonal beams can be employed to alleviate the MUI. Since each user has dominant beams around the line of sight direction, beam selection can reduce the power consumption of radio frequency chain. In this paper, we formulate the problem of maximizing the sum rate of all users by optimizing the beam selection for beamspace and UAV-BS deployment in mmWave UAV-BS system. This nonconvex problem is solved in two steps. First, we propose a signal to interference plus noise ratio based greedy beam selection scheme to ensure that all the ground users in the given area can be served by the UAV-BS, where a zeroforcing precoding scheme is used to eliminate the MUI. Then, we utilize the continuous genetic algorithm to find the optimal UAV-BS deployment and beam pattern to maximize the sum rate of all users. Moreover, considering the mobility of the UAVBS, the UAV-BS trajectory and beam selection for beamspace are optimized in the mmWave UAV-BS system. The simulation results demonstrate the effectiveness of the proposed design for the mmWave UAV-BS system

Air-to-ground NOMA systems for the “Internet-Above-the-Clouds”

The provision of high-speed Internet access in aircraft is mainly supported by satellite links at the time of writing, aided by links between the aircraft and the ground stations. It is anticipated that Air-To-Ground (A2G) communications between en-route aircraft and the ground stations will have a major role in providing the required Quality of Service, while complying with the low latency requirements of next generation communications. Non-Orthogonal Multiple Access (NOMA) systems will increase the system throughput by allowing multiple aircraft to simultaneously communicate with the ground station, while requiring fewer resource slots. Due to the limited number of orthogonal resources and the high number of aircraft, interference is expected to be present. In this contribution, we employ beamforming based on the Angle of Arrival (AoA) of the signals and antenna arrays having multiple antenna elements, as well as a novel interference-exploiting Sphere Decoder (iSD), which detects the signals of the supported users, while beneficially exploiting those of the interfering users. We show that an improved performance may be achieved in both Hard-Input Hard-Output (HIHO) scenarios, as well as in iterative Soft-Input Soft-Output (SISO) scenarios, when compared to the conventional Sphere Decoder, the Maximum Likelihood (ML) detector and the Maximum A posteriori Probability (MAP) detector. We also characterize the complexity of the proposed receiver and evaluate its performance with the aid of BER simulations and EXtrinsic Information Transfer (EXIT) charts

Research Data: Air-to-ground NOMA Systems for the “Internet-Above-the-Clouds”

The dataset for the paper published in IEEE Access by Panagiotis Botsinis et al: Air-to-ground NOMA Systems for the &ldquo;Internet-Above-the-Clouds&rdquo; </span