Spectrum Sharing Backhaul Satellite-Terrestrial Systems via Analog Beamforming
Spectrum Sharing Backhaul Satellite-Terrestrial Systems via Analog Beamforming
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DOI：
10.1109/jstsp.2018.2824980
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发表时间：
2018-05-01
影响因子：
7.5
通讯作者：
Perez-Neira, Ana I.
中科院分区：
文献类型：
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作者：
Angel Vazquez, Miguel;Blanco, Luis;Perez-Neira, Ana I.
当前的卫星和地面回程系统部署在不相交的频带中。这一事实阻碍了频谱的有效利用，并限制了无线回程网络的发展。在本文中，我们提出了一种干扰抑制技术，以允许卫星和地面回程链路之间的频谱共存。该干扰消除器在地面回程节点上实施，假设配备多个天线。由于这些系统需要大带宽和大量天线，我们考虑纯模拟波束成形。准确地说，我们假设相控阵波束形成配置，使得地面回程节点只能通过改变每个波束形成权重的相位来减少干扰。考虑两种情况：18 和 28 GHz 频段，其中应分别解决发射和接收波束成形优化问题。在这两种情况下，优化问题都会导致非凸问题，我们建议通过两种替代的凸近似方法来解决。对这两种方法进行了评估，发现相对于上限解决方案，它们的阵列增益损失小于 1 dB。最后，所提出的频谱共享方案的频谱效率增益在数值模拟中得到验证。
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 nonconvex problem that 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.