Paper Info
Title
Uplink Performance of Cell-Free Massive MIMO With Multi-Antenna Users Over Jointly-Correlated Rayleigh Fading Channels
Abstract
In this paper, we investigate a cell-free massive MIMO system with both access points (APs) and user equipments (UEs) equipped with multiple antennas over jointly-correlated Rayleigh fading channels. We study four uplink implementations, from fully centralized processing to fully distributed processing, and derive their achievable spectral efficiency (SE) expressions with minimum mean-squared error successive interference cancellation (MMSE-SIC) detectors and arbitrary combining schemes. Furthermore, the global and local MMSE combining schemes are derived based on full and local channel state information (CSI) obtained under pilot contamination, which can maximize the achievable SE for the fully centralized and distributed implementation, respectively. We study a two-layer decoding implementation with an arbitrary combining scheme in the first layer and optimal large-scale fading decoding (LSFD) in the second layer. Besides, we compute novel closed-form SE expressions for the two-layer decoding implementation with maximum ratio (MR) combining. In the numerical results, we compare the SE performance for different implementation levels, combining schemes, and channel models. It is important to note that increasing the number of antennas per UE may degrade the SE performance.
Year
DOI
Venue
2022
10.1109/TWC.2022.3158353
IEEE Transactions on Wireless Communications
Keywords
DocType
Volume
Cell-free massive MIMO,Weichselberger model,MMSE processing,spectral efficiency
Journal
21
Issue
ISSN
Citations 
9
1536-1276
1
PageRank 
References 
Authors
0.35
20
5
Name
Order
Citations
PageRank
Zhe Wang1122.50
Jiayi Zhang291174.44
Bo Ai31581185.94
Chau Yuen44493263.28
Mérouane Debbah58575477.64