Open AccessIterative AP selection, MMSE precoding and power allocation in cell‐free massive MIMO systems
Author(s) -
Palhares Victoria M.T.,
Lamare Rodrigo C.,
Flores André R.,
Landau Lukas T.N.
Publication year - 2020
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2020.0627
Subject(s) - precoding , telecommunications link , computer science , minimum mean square error , mimo , beamforming , channel state information , zero forcing precoding , channel (broadcasting) , iterative method , mathematical optimization , control theory (sociology) , algorithm , mathematics , telecommunications , wireless , statistics , estimator , control (management) , artificial intelligence
In this work, the authors proposed the iterative access point (AP) selection (APS), linear minimum mean‐square error (MMSE) precoding and power allocation techniques for cell‐free massive multiple‐input multiple‐output (MIMO) systems. They considered the downlink channel with single‐antenna users and multiple‐antenna APs. They derive sum‐rate expressions for the proposed iterative APS techniques followed by MMSE precoding and optimal, adaptive, and uniform power allocation schemes. Simulations show that the proposed approach outperforms existing conjugate beamforming and zero‐forcing schemes and that performance remains excellent with APS, in the presence of perfect and imperfect channel state information.