User-centric distributed signal processing algorithms for next generation cell-free massive MIMO based wireless communication networks

The project considers so-called cell-free massive MIMO (CFmMIMO) systems for next-generation wireless communication networks. Unlike in current cellular systems, where a user is served only by the one access point (AP) of the cell in which it resides, in a CFmMIMO system a user may be served by all APs in the network. This can resolve current interference issues and potentially offer significantly higher spectral efficiency. The goal of the project will be to develop novel and efficient distributed signal processing algorithms, to reap the full CFmMIMO benefits at a practically affordable cost, i.e., not relying on centralized processing and with a computational complexity and inter-AP communication cost that is scalable for large networks with many users and many APs. A user-centric approach will be taken, where a user is served by a selected set of APs, forming local ad-hoc networks that optimally cooperate by sharing fused signals and parameters as coordinated by the distributed algorithms. Specific signal processing challenges will be addressed in this general context, namely synchronization, channel estimation, equalization, precoding, and resource allocation. The project will build on earlier research on distributed node-specific signal estimation in wireless (acoustic) sensor networks, resource allocation in fixed-access DSL networks, as well as on in-house expertise in experimentally-driven mMIMO channel estimation and distributed signal processing.