Uplink Spectral and Energy Efficiency of Cell-Free Massive MIMO With Optimal Uniform QuantizationShow others and affiliations
2021 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 69, no 1, p. 223-245Article in journal (Refereed) Published
Abstract [en]
This paper investigates the performance of limited-fronthaul cell-free massive multiple-input multiple-output (MIMO) taking account the fronthaul quantization and imperfect channel acquisition. Three cases are studied, which we refer to as Estimate&Quantize, Quantize&Estimate, and Decentralized, according to where channel estimation is performed and exploited. Maximum-ratio combining (MRC), zero-forcing (ZF), and minimum mean-square error (MMSE) receivers are considered. The Max algorithm and the Bussgang decomposition are exploited to model optimum uniform quantization. Exploiting the optimal step size of the quantizer, analytical expressions for spectral and energy efficiencies are presented. Finally, an access point (AP) assignment algorithm is proposed to improve the performance of the decentralized scheme. Numerical results investigate the performance gap between limited fronthaul and perfect fronthaul cases, and demonstrate that exploiting relatively few quantization bits, the performance of limited-fronthaul cell-free massive MIMO closely approaches the perfect-fronthaul performance.
Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC , 2021. Vol. 69, no 1, p. 223-245
Keywords [en]
Bussgang decomposition, cell-free massive MIMO, C-RAN, energy efficiency, quantization, optimal uniform quantization
National Category
Signal Processing Telecommunications
Identifiers
URN: urn:nbn:se:kth:diva-296045DOI: 10.1109/TCOMM.2020.3028305ISI: 000608689300016Scopus ID: 2-s2.0-85099765060OAI: oai:DiVA.org:kth-296045DiVA, id: diva2:1663846
Note
QC 20220615
2022-06-022022-06-022022-06-25Bibliographically approved