MmWave UAV Networks With Multi-Cell Association: Performance Limit and Optimization

Abstract

This paper aims to exploit the fundamental limits on the downlink coverage and spatial throughput performances of a cellular network consisting of a tier of unmanned aerial vehicle (UAV) base stations (BSs) using the millimeter wave (mmWave) band and a tier of ground BSs using the ultra high frequency (UHF) band. To reduce handover signaling overhead, the ground BSs take charge of control signaling delivery whereas the UAVs are in charge of payload data transmission so that users need to simultaneously associate with a ground BS and a UAV in this network with a control-data plane-split architecture. We first propose a three-dimensional (3D) location distribution model of the UAVs using stochastic geometry which is able to generally characterize the positions of the UAVs in the sky. Using this 3D distribution model, we propose the multi-cell coverage probability and the volume spectral efficiency of the network, derive their explicit low-complexity expressions and find their upper limits when each of the UAVs and ground BSs is equipped with a massive antenna array. We further show that the multi-cell coverage probability and the volume spectral efficiency can be maximized by optimally deploying and positioning the UAVs in the sky and thereby their fundamental maximal limits are found. These important analytical findings are validated by numerical simulations.Index Terms-Unmanned aerial vehicle network, millimeter wave, coverage, throughput, cell association, stochastic geometry. arXiv:1905.06099v3 [cs.IT] 18 Jul 2019 by a clustered channel model consisting of small-scale fading and angle-ofdeparture (AoD)-based transmit array gain vectors. Here we thus assume that all UAVs have a uniform linear array and are able to perfectly align their beam with the angle-of-departure (AoD) of their array in order to maximize their antenna array gain from them to their serving users.

Performance, Fairness, and Tradeoff in UAV Swarm Underlaid mmWave Cellular Networks With Directional Antennas

“…Simulation results show that the date rate under mmWave outperforms that under sub-6 GHZ, due to the direction beamforming and large bandwidth in mmWave. Using stochastic geometry, the multicell coverage and volume spectral efficiency are derived in UAV underlaid mmWave cellular networks [35]. The intensity and the positions of the UAVs are optimized for maximizing these two performance metrics.…”

Performance Optimization in UAV‐Assisted Wireless Powered mmWave Networks for Emergency Communications

“…However, UAVenabled cellular architecture over mmWave frequency band has been recognized as one of the best solution for ondemand high data rate service. Therefore, the many existing works focused on UAV-assisted mmWave communications [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

“…The authors of [33] designed a spectrum management architecture for mmWave swarm networks with UAVs acting as flying BSs, which considered the issues of interference, energy consumption, and UAV mobility. The authors of [34] derived the multicell probability and the volume spectral efficiency for UAVassisted mmWave cellular networks by using stochastic geometry.…”

“…The authors of [34] proposed a 3D location distribution model to characterize the positions of the UAVs by using stochastic geometry and considered multicell coverage probability and volume spectral efficiency as metrics to study the performance of mmWave networks with UAVs acting as aerial BSs. The beam formed by the mmWave antenna array has strong directivity and needs multiple beam scans to cover the whole region, so the authors of [38] proposed a sectoring approach to ensure coverage of the whole region.…”

Gateway Selection in Millimeter Wave UAV Wireless Networks Using Multi-Player Multi-Armed Bandit

“…Accordingly, mmWave coverage is limited to be within a few meters around the mmWave transmitter, which mandates the use of relaying to extend its coverage range [ 13 ]. Integrating millimeter wave (mmWave) band, 30~300 GHz, communications with UAV BSs can sustain 5G/B5G requirements due to the large available bandwidth [ 14 , 15 ]. Moreover, UAVs can address many of mmWave challenges, such as the construction of autonomous mmWave relays [ 16 ].…”