Interference Mitigation in Coexisting Satellites and Cloud-Assisted Ground Networks in the mmWave Band

Abstract

Given the drastic demand for stringent digital services, augmenting terrestrial communications with satellite services promises to meet the rush-to-gold-like demand for scarce radio resources. Our paper investigates the problem of coexisting satellite-ground networks consisting of several satellites and several ground base-stations, all operating at the millimeter-wave band. Such coexistence of space and ground communications becomes prone to wireless interference, and so the cross-development of intelligent resource allocation techniques becomes indispensable for assessing the benefit of such hybrid space-ground networks. The paper assumes that a fraction of the ground base-stations connects to a centralized computing processor (i.e., cloud) using fronthaul links with limited capacity. The paper further assumes that each satellite connects with its own earth-station, which in turn connects with a ground base-station, hereafter denoted by satellite-associated base-station, that aims at serving a part of the ground-users. The system performance depends, therefore, on both the intra- and inter-mode interference between the satellites and cloud-connected base-stations, and the integrated access-backhaul interference between the satellite to earth-station and satellite-associated base-station to users. The paper then aims at maximizing the sum rate of the considered network under power, user-connectivity, and ground fronthaul constraints, in order to jointly determine the satellite-associated base-stations and cloud-connected base-stations served users’ beamforming vectors. The paper addresses such an intricate non-convex optimization problem using a combination of well-chosen inner convex approximations, coupled with proper outer loop correction steps. The numerical simulations show how effective our proposed algorithm is at mitigating the system multi-mode interference, particularly in congested networks.