  We propose a decentralized receiver for extra-large multiple-input
multiple-output (XL-MIMO) arrays. Our method operates with no central
processing unit (CPU) and all the signal detection tasks are done in
distributed nodes. We exploit a combined message-passing framework to design an
uncoordinated detection scheme that overcomes three major challenges in the
XL-MIMO systems: computational complexity, scalability and non-stationarities
in user energy distribution. Our numerical evaluations show a significant
performance improvement compared to benchmark distributed methods while
operating very close to the centralized receivers.
