Some 5G challenges at the beginning of the project
- New frequencies: Higher frequencies and larger bandwidths
- mmWave transmissions for both indoor and outdoor
- since the beginning of the project: 26GHz and 72 GHz bands have been defined
- Improvment of the spectral efficiency
- By increasing the number of antennas: massive MIMO
Main challenges for M5HESTIA project
- Improve the link budget
- The high path losses in millimeterwave impose to use directive antenna with very high gains to ensure a sufficient SNR (Signal to Noise Ratio)
- HW implementation is very critical: calibration, interference, integration losses…
- Increase of the number of antennas
- Massive MIMO: main theoretical studies assume as many RF chains as many antennas but increasing the number of antenna RF chains at high frequencies lead to a lot of problems such as the complexity in terms of algorithms and HW integration, the system consumption…
- Hybrid massive MIMO
- less number of RF chains, several antennas linked to one RF chain
- optimisation: trade-off between the number of antennas and the number of RF chains
- Channel measurements and channel modelling
- Need of channel models for theoretical studies
- Development of a deterministic channel simulator well suited for 5G mmW scenarios
- Need of new channel sounders: in both elevation and azimuth, for both indoor and outdoor communications
- Exploitation of indoor and outdoor data from Aalto University
- Need of tracking position and orientation algorithm studies
- Need of channel models for theoretical studies
- Develop proofs of concept by designing one HW platform that integrates powerful analog and digital parts
- To Implement new enablers
- To integrate new services
- To validate the use of new frequencies
- To make experiments
