|Date||2023.11.17 (15：00 - 17：00)|
Meeting ID:825 5899 4133
|Speaker||Dr. Antti Tölli|
|Affiliation||University of Oulu (Finland)|
|Title||"Distributed Unicast and Multicast Precoding Design via Over-the-Air Signaling for Cell-Free Massive MIMO"
Most works on cell-free massive multiple-input multiple-output (MIMO) consider non-cooperative precoding strategies at the base stations (BSs) to avoid extensive channel state information (CSI) exchange via backhaul signaling. However, considerable performance gains can be achieved by allowing for (limited) coordination among the BSs. This talk introduces a fully distributed framework for cooperative precoding design in cell-free massive MIMO (and, more generally, in joint transmission coordinated multi-point) systems that entirely eliminates the need for backhaul signaling for CSI exchange. The proposed novel over-the-air (OTA) signaling mechanism allows each BS to obtain the same cross-term information that is traditionally exchanged among the BSs via backhaul signaling. To design the joint network-wide unicast and multi-group multicast precoders at the BSs and the combiners at the user equipment (UE) in a fully distributed fashion, we adopt an iterative bi-directional training scheme with UE-specific and/or group-specific precoded uplink and downlink pilots. The proposed distributed precoding designs enjoy desirable flexibility and scalability properties, as the amount of OTA signaling does not scale with the number of BSs or UEs. Numerical results show fast convergence and remarkable performance gains compared with non-cooperative precoding designs. The proposed schemes can also outperform centralized precoding designs under realistic CSI acquisition.
|Intended for||Everyone is welcome to join.|
|Co-Organized by||Institute of Global Innovation “Life Science” Umebayashi Team
Excellent Leader Development for Super Smart Society by New Industry Creation and Diversity
|Contact||Institute of Global Innovation Research, Institute of Engineering
Prof. Kenta Umebayashi
e-mail: ume_k (at) cc.tuat.ac.jp