TY - JOUR
T1 - Multipair Two-Way DF Relaying with Cell-Free Massive MIMO
AU - Papazafeiropoulos, Anastasios K.
AU - Kourtessis, Pandelis
AU - Chatzinotas, Symeon
AU - Senior, John M.
N1 - Funding Information:
This work was supported in part by the University of Hertfordshire's 5-year Vice Chancellor's Research Fellowship; and in part by the National Research Fund, Luxembourg, under the Projects ECLECTIC and 5G-SKY.
Publisher Copyright:
© 2020 IEEE.
PY - 2021
Y1 - 2021
N2 - We consider a two-way half-duplex decode-and-forward (DF) relaying system with multiple pairs of single-antenna users assisted by a cell-free (CF) massive multiple-input multiple-output (mMIMO) architecture with multiple-antenna access points (APs). Under the practical constraint of imperfect channel state information (CSI), we derive the achievable sum spectral efficiency (SE) for a finite number of APs with maximum ratio (MR) linear processing for both reception and transmission in closed-form. Notably, the proposed CF mMIMO relaying architecture, exploiting the spatial diversity, and providing better coverage, outperforms the conventional collocated mMIMO deployment. Moreover, we shed light on the power-scaling laws maintaining a specific SE as the number of APs grows. A thorough examination of the interplay between the transmit powers per pilot symbol and user/APs takes place, and useful conclusions are extracted. Finally, differently to the common approach for power control in CF mMIMO systems, we design a power allocation scheme maximizing the sum SE.
AB - We consider a two-way half-duplex decode-and-forward (DF) relaying system with multiple pairs of single-antenna users assisted by a cell-free (CF) massive multiple-input multiple-output (mMIMO) architecture with multiple-antenna access points (APs). Under the practical constraint of imperfect channel state information (CSI), we derive the achievable sum spectral efficiency (SE) for a finite number of APs with maximum ratio (MR) linear processing for both reception and transmission in closed-form. Notably, the proposed CF mMIMO relaying architecture, exploiting the spatial diversity, and providing better coverage, outperforms the conventional collocated mMIMO deployment. Moreover, we shed light on the power-scaling laws maintaining a specific SE as the number of APs grows. A thorough examination of the interplay between the transmit powers per pilot symbol and user/APs takes place, and useful conclusions are extracted. Finally, differently to the common approach for power control in CF mMIMO systems, we design a power allocation scheme maximizing the sum SE.
KW - beyond 5G MIMO
KW - decode-and-forward
KW - power-scaling law
UR - http://www.scopus.com/inward/record.url?scp=85114515013&partnerID=8YFLogxK
U2 - 10.1109/OJCOMS.2021.3060661
DO - 10.1109/OJCOMS.2021.3060661
M3 - Article
AN - SCOPUS:85114515013
SN - 2644-125X
VL - 2
SP - 423
EP - 438
JO - IEEE Open Journal of the Communications Society
JF - IEEE Open Journal of the Communications Society
M1 - 9360649
ER -