IMPLEMENTATION OF MASSIVE MIMO FOR 5G BROADBAND COMMUNICATION SATELLITES (ARTES 4.0 SPL 5G/6G 5B.252) - EXPRO+

Objective: The objective of the activity is to develop new Active Antenna Systems with high flexibility to adapt to traffic requestwith increased total capacity and limited payload complexity. Targeted Improvements:40% throughput increase;50% beamforming complexity reduction;Description: MIMO (multiple-input multiple-output) has become increasingly important in the last generation of wireless networks, and Massive-MIMO (M-MIMO) is the key enabling technology of 5G networks. MIMO allows to maximise the reuse of the limited frequency resources and, in mobile networks, to mitigate the channel fading effects. The exploitation of MMIMO in the forward link of satellite systems requires large on-board active arrays which are subject of ongoing developments, however, the adoption of conventional Massive- MIMO for SatComs several technical challenges. Early approaches were based on accurate estimation of the Channel State Information (CSI), thus requiring regular reporting from the user equipment and tight control of the satellite payload radio frequency chains differential phase and amplitude error, to avoid performance degradation. The CSI update rate is even higher for Low Earth Orbiting (LEO) satellites due to the system orbital dynamic. Recent research has identified a number of key simplifications possible:- Replacing the channel state information with the user location information;- Converting the MIMO precoding into beam steering;- Making use on-board of Fast Fourier Transform beamforming and beam switching;- Approximating the Np-hard Radio Resource Management (RRM) with a linear complexity fast algorithm. and such pragmatic M-MIMO approach is showing excellent performance in non-uniform traffic scenarios with different distributions of the users.In this activity, pragmatic M-MIMO solutions will be further developed and applied to 5G and 6G via satellite. A scaled demonstrator, including a representative transmit active array with associated beamforming network, will be manufactured and tested with associated RRM processing, in order to verify the beamforming and RRM approach and associated advantages as compared to conventional MIMO schemes. The activity shall also estimate the Radio Access Network (RAN) implementation complexity.