This paper takes a new look at Cell-free Massive MIMO (multiple-input
multiple-output) through the lens of the dynamic cooperation cluster framework
from the Network MIMO literature. The purpose is to identify and address
scalability issues that appear in prior work. We provide distributed algorithms
for initial access, pilot assignment, cluster formation, precoding, and
combining that are scalable in the sense of being implementable with
arbitrarily many users. Interestingly, the suggested precoding and combining
outperform conjugate beamforming and matched filtering, respectively, while
also being fully distributed.Comment: To appear at the 2019 IEEE International Symposium on Personal,
Indoor and Mobile Radio Communications (IEEE PIMRC 2019), 6 pages, 5 figure