Paper Info
Title
Cell-Free Massive MIMO-OFDM for High-Speed Train Communications
Abstract
Cell-free (CF) massive multiple-input multiple-output (MIMO) systems show great potentials in low-mobility scenarios, due to cell boundary disappearance and strong macro diversity. However, the great Doppler frequency offset (DFO) leads to serious inter-carrier interference in orthogonal frequency division multiplexing (OFDM) technology, which makes it difficult to provide high-quality transmissions for both high-speed train (HST) operation control systems and passengers. In this paper, we focus on the performance of CF massive MIMO-OFDM systems with both fully centralized and local minimum mean square error (MMSE) combining in HST communications. Considering the local maximum ratio (MR) combining, the large-scale fading decoding (LSFD) cooperation and the practical effect of DFO on system performance, exact closed-form expressions for uplink spectral efficiency (SE) expressions are derived. We observe that cooperative MMSE combining achieves better SE performance than uncooperative MR combining. In addition, HST communications with small cell and cellular massive MIMO-OFDM systems are compared in terms of SE. Numerical results reveal that the CF massive MIMO-OFDM system achieves a larger and more uniform SE than the other systems. Finally, the train antenna centric (TA-centric) CF massive MIMO-OFDM system is designed for practical implementation in HST communications, and three power control schemes are adopted to optimize the propagation of TAs for reducing the impact of the DFO.
Year
DOI
Venue
2022
10.1109/JSAC.2022.3196088
IEEE Journal on Selected Areas in Communications
Keywords
DocType
Volume
Cell-free massive MIMO-OFDM,high-speed train,inter-carrier interference,spectral efficiency
Journal
40
Issue
ISSN
Citations 
10
0733-8716
0
PageRank 
References 
Authors
0.34
33
5
Name
Order
Citations
PageRank
Jiakang Zheng1284.84
Jiayi Zhang291174.44
Emil Björnson33446171.49
Zhetao Li441938.45
Bo Ai51581185.94