Title: The harmful influence of employing a large number of pilot-resources on the performance of massive MIMO systems

Authors: Abdelfettah Belhabib; Mohamed Boulouird; Moha M'Rabet Hassani

Addresses: Faculty of Sciences Semlalia, Instrumentation, Signals and Physical Systems (I2SP) Group, Cadi Ayyad University, Marrakesh, 40000, Morocco ' Smart Systems and Applications (SSA) Group, National School of Applied Sciences of Marrakesh (ENSA-M), Cadi Ayyad University, Marrakesh, 40000, Morocco ' Faculty of Sciences Semlalia, Instrumentation, Signals and Physical Systems (I2SP) Group, Cadi Ayyad University, Marrakesh, 40000, Morocco

Abstract: One of the severe constraints that limit the implementation of massive multi-input multi-output (M-MIMO) systems is called pilot contamination (PC). To overcome this problem, soft pilot reuse (SPR) strategy was proposed, which aims to properly allocate the Pilot Sequences (PS) to the users based on their properties e.g., Quality-of-Service. Despite its flaws, which can damage the spectral efficiency, the SPR strategy has been, heavily, employed as a decontaminating strategy. To reveal the weakness of this approach, this paper adopts a SPR based-strategy that separates the users within cells based on their large scale fading coefficients, therefore, because the edge-users (EUs) are mostly affected by the PC compared to the centre-users (CUs), a set of orthogonal pilots is allocated to the EUs of the overall cells, while the CUs of each cell are obliged to reuse the same set of orthogonal pilots as the CUs of adjacent cells.

Keywords: massive MIMO; pilot contamination; SPR; soft pilot reuse; pilot overhead; conventional strategy; 5G wireless communications.

DOI: 10.1504/IJMIC.2021.123365

International Journal of Modelling, Identification and Control, 2021 Vol.38 No.3/4, pp.231 - 240

Received: 19 May 2020
Accepted: 12 Jan 2021
Published online: 13 Jun 2022 *

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