Hybrid network management scheme for improving backhauling networks

SANSA introduce new elements in the backhauling network to boost the performance of mobile wireless backhaul networks in terms of capacity, energy efficiency and resilience against link failure or congestion, while easing the deployment in both rural and urban areas and assuring at the same time an efficient use of the spectrum. In particular, the interaction of a centralized element (Hybrid Network Manager) and distributed ones (Intelligent Backhaul Nodes) allows an efficient exploitation of all network resources being them terrestrial or satellite.

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Hybrid Analog-Digital Transmit Beamforming for Spectrum Sharing Satellite-Terrestrial Systems

Hybrid multiantenna architectures are ideal for high throughput wireless links, where full-digital solutions are extremely expensive due to their the high number of radiofrequency chains and full-analog architectures require complex and lossy beamforming networks. In contrast to the recent works regarding mm-wave precoding, we consider the case where the transmitter is required to limit its array gain to certain angles-of-departure where non-intended receivers are located.
This is of great importance in the 18 GHz band where wireless backhaul systems can eventually share the spectrum with satellite systems, leading to a substantial reduction of the spectrum license cost. We propose a general optimization framework based on an alternate analog-digital optimization that can consider any arbitrary sub-array scheme (i.e. interleaved, localized, etc.)

Phase-Only Transmit Beamforming for Spectrum Sharing Microwave Systems

Digital beamforming needs a large number of computational resources compared to analog beamforming, which only needs a single radio-frequency chain, results the less computational demanding solution. Analog schemes are usually composed by a phase shifter network whose elements transmit at a certain fixed power so that the system designer shall compute the phase values for each element given a set of directions. This approach leads to non-convex quadratic problems where the traditional semidefinite relaxation fails to deliver satisfactory outcomes. In order to solve this, we propose a non-smooth method that behaves well in several scenarios.

Robust multi-cell precoding over load-controlled beams with single-fed antenna arrays

In this work, we present a method that enables the application of robust, low-complexity, arbitrary, single-cell and multi-cell channel-aware precoding at single-fed load controlled parasitic antenna arrays. Moreover, we derive closed-form asymptotic expressions for the sum rate capacity bounds and we evaluate numerically the sum rate throughput attainable by various multi-cell precoding schemes for given beam patterns and propagation conditions. We compare the performance of these transmission strategies against the theoretically derived bounds, as well as against the one accomplished with equivalent single-fed configurations. The simulation results confirm the expected performance gains of the proposed approach over the conventional single-fed setup.

Coordinated MIMO with Single-fed Load-Controlled Parasitic Antenna Arrays

In this work, we present a method that enables the application of robust, low-complexity, arbitrary channel-aware precoding at single-fed load-controlled parasitic antenna arrays. Moreover, we describe the extension of this technique to multi-cell setups. Finally, we evaluate the sum-rate throughput performance of several multi-cell precoding schemes through numerical simulations based on realistic radiation patterns generated by antenna design software as well as on a scattering environment model. The results of the simulations confirm the expected performance gains over conventional single-fed configurations.