Spectrum Sharing Backhaul Satellite-Terrestrial Systems via Analog Beamforming

Abstract

Abstract-Current satellite and terrestrial backhaul systems are deployed in disjoint frequency bands. This fact precludes an efficient use of the spectrum and limits the evolution of wireless backhauling networks. In this paper, we propose an interference mitigation technique in order to allow the spectrum coexistence between satellite and terrestrial backhaul links. This interference reliever is implemented at the terrestrial backhaul nodes which are assumed to be equipped with multiple antennas. Due to the large bandwidth and huge number of antennas required in these systems, we consider pure analog beamforming. Precisely, we assume a phased array beamforming configuration so that the terrestrial backhaul node can only reduce the interference by changing the phases of each beamforming weight. Two cases are considered: the 18 and 28 GHz band where transmit and receive beamforming optimization problems shall be tackled respectively. In both cases, the optimization problem results in a non-convex problem which we propose to solve via two alternative convex approximation methods. These two approaches are evaluated and they present less than 1 dB array gain loss with respect to the upper bound solution. Finally, the spectral efficiency gains of the proposed spectrum sharing scenarios are validated in numerical simulations.

A Distributed Collaborative Game-Theoretic Approach in Cognitive Satellite Communication Networks

“…In the spectrum sharing between satellite communications and terrestrial communications, some of the schemes work in the overlay mode [8], [9]. When operating in this mode, terrestrial users are often cognitive users, satellite users are often primary users, and both use the same frequencies.…”

Optimized Power Control Scheme for Global Throughput of Cognitive Satellite-Terrestrial Networks Based on Non-Cooperative Game

“…One spectrum coexistence scenario between fixed satellite service (FSS) system and terrestrial cognitive radio system shown in Fig. 1 is considered in this paper, where the FSS system acts as the primary network and shares the spectrum resource with the terrestrial secondary network [13]- [15]. In the considered scenario, the FSS system consists of a geosynchronous (GEO) satellite S and one earth station E located in the center of a circular area with radius l, and M CBSs of the secondary network follow uniform distribution in this circular area.…”

“…3GPP, ITU, ETSI) and researchers have recently been focused on the extension of the cognitive radio concept to satellite-terrestrial networks [7]- [9]. At present, a tremendous amount of effort has been made to explore a new network architecture that allows satellite networks to coexist with terrestrial networks in the same frequency band through CR techniques [10]- [15]. As a result, the cognitive satellite-terrestrial networks (CSTNs) with high spectrum efficiency have been proposed as a promising solution.…”

“…On the basis of access technology of secondary users, potential cognitive techniques for CSTNs can be classified into interwave, underlay and overlay approaches [13]. Considering the sparsity of satellite users in geographically and the wide coverage of satellite beams, the current research on CSTNs mainly focuses on the underlay fashion, which is considered as a solution for the future spectrum needs [14], [15]. However, the interference from cognitive base stations (CBSs) to satellite links and the inter-cell interference among CBSs are inevitable in the CSTNs with underlay scheme.…”

Low-cost hybrid analog-digital beamformer evaluation in spectrum sharing systems

“…Concretely, we propose a variation of FPP-SCA in [8]. For more details, the reader can refer to [11]. When an hybrid analogdigital beamforming design is targeted, the optimization problem shall be reconsidered.…”