Cell-Free Massive MIMO: User-Centric Approach

Recently, the so-called cell-free (CF) massive MIMO architecture has been introduced, wherein a very large number of distributed access points simultaneously and jointly serve a much smaller number of mobile stations. This letter introduces a user-centric (UC) virtual cell approach to CF massive MIMO, wherein each user is served only by a limited number of access points. The UC approach requires less backhaul overhead than the CF approach, and outperforms the latter in terms of achievable rate-per-user for the vast majority of the users in the network.