Optimal Power Allocation and Clustering in Cell-Free Wireless Networks

Abstract

Cell-free wireless networks have garnered significant interest within the research community due to their potential to eliminate cell-edge effects and exploit macro-diversity. In this paper, we design algorithms to jointly optimize uplink transmit powers and dynamic user-centric clusters within a cell-free network. This strategy aims to effectively mitigate inter-user interference and attain spectral efficiency targets for users in a scalable manner. To serve this goal, we re-purpose a classic iterative algorithm and prove its convergence for both the maximum ratio combiner (MRC) and linear minimum mean square error (LMMSE) receivers. We present several access point (AP) subset selection schemes of varying complexity and demonstrate how clustering requirements differ according to receiver capabilities. In particular, we show that optimizing the serving cluster for each user is crucial when using the simple MRC receiver.