scholarly journals Graph Coloring Based Pilot Allocation to Mitigate Pilot Contamination for Multi-Cell Massive MIMO Systems

2015 ◽  
Vol 19 (10) ◽  
pp. 1842-1845 ◽  
Author(s):  
Xudong Zhu ◽  
Linglong Dai ◽  
Zhaocheng Wang
Keyword(s):  
Graph Coloring ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Pilot Contamination ◽  
Pilot Allocation

scholarly journals Massive MIMO User Location Based Pilot Allocation in Massive MIMO Systems

2020 ◽  
Vol 9 (5) ◽  
pp. 204-210
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Polar Angle ◽  
Base Station ◽  
Polar Coordinate System ◽  
Pilot Contamination ◽  
Pilot Allocation ◽  
Polar Coordinate ◽  
Speed Simulation ◽  
User Location

Aiming at the problem of massive MIMO pilot contamination, a user location information based pilot allocation scheme is proposed. The proposed scheme sorts the users and assigns pilots in accordance to the polar angle of the user's location in the polar coordinate system with the base station of the cell as the pole. The scheme combines the characteristics of the directional large line, and by controlling the reuse distance of the pilots in a relatively long range, the goals of reducing pilot contamination is improving system reachability and speed. Simulation results show that the proposed scheme not only effectively reduce pilot contamination among users, but also improves the performance gap between different users with the improved system fairness

scholarly journals Smart Switching Strategy-Based Supervision Rule to Mitigate the Problem of Pilot Contamination in Massive MIMO Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Abdelfettah Belhabib ◽  
Mohamed Boulouird ◽  
Moha M’Rabet Hassani
Keyword(s):  
Graph Coloring ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Weighted Graph ◽  
Achievable Rate ◽  
Pilot Contamination ◽  
Block Diagonalization ◽  
Switching Strategy ◽  
Simulation Results ◽  
Contamination Problem

Despite the large benefits that can be fulfilled through the exploitation of Massive Multi-input Multioutput (M-MIMO), this technology still constrained by a well-known constraint, called as pilot contamination problem (PCP), which is the main consequence of, simultaneously, reusing the same set of orthogonal pilot sequences (OPSs) for the users of several cells. Due to the scarcity of the OPS resources, the reuse of the same set of the OPSs for the users of different cells is unavoidable. Hence, this work proposes a novel decontaminating strategy, which is aimed at guaranteeing a trade-off between the use of the OPSs and the mitigation of the PCP. Specifically, to make the use of the available OPSs better, we propose the consolidation of two powerful decontaminating strategies. Under a derived supervision rule (SR), these strategies are the soft pilot reuse-based multicell block diagonalization precoding (SPR-MBDP) and the weighted graph coloring-based pilot assignment (WGC-PA). The SR enables the switching mechanism between the two strategies, which leads to address the PCP with a fewer number of the OPSs compared to the SPR-MBDP, therefore boosting the per-cell achievable rate. Simulation results prove the effectiveness of our proposed strategy.

scholarly journals Partial Pilot Allocation Scheme in Multi-Cell Massive MIMO Systems for Pilot Contamination Reduction

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3163
Author(s):  
Ahmed S. Al-hubaishi ◽  
Nor Kamariah Noordin ◽  
Aduwati Sali ◽  
Shamala Subramaniam ◽  
Ali Mohammed Mansoor ◽  
...  
Keyword(s):  
Massive Mimo ◽  
Large Scale ◽  
Mimo Systems ◽  
Cellular Systems ◽  
Cumulative Distribution ◽  
Pilot Contamination ◽  
Allocation Scheme ◽  
Pilot Allocation ◽  
Allocation Process ◽  
Simulation Results

Inter-cell interference has been identified as one of the major challenges of multiple-input–multiple-output (MIMO)-enabled cellular systems. This problem occurs when the same pilot sets are reused across adjacent cells to save bandwidth for data transmission. As a result, so-called pilot contamination occurs, which cannot be mitigated with an increased number of serving antennas. In this work, we proposed a partial pilot allocation scheme (PPA) to tackle the pilot contamination problem and consequently improve the uplink throughput of users in multi-cell massive MIMO systems. This was achieved by using the large-scale characteristics of the fading channel to keep users with a weak channel condition out of the effect of severe interference during the pilot allocation process. Simulation results showed that the proposed scheme outperformed both smart pilot allocation (SPA) and conventional schemes. In particular, PPA improved the uplink rate by 30% compared to the SPA—a recently proposed schema. Furthermore, our simulation results clearly showed that PPA improved the cumulative distribution function (CDF) of the signal-to-interference-plus-noise ratio (SINR) and uplink throughput.

Pilot contamination mitigation under smart pilot allocation strategies within massive MIMO-5G system

2021 ◽  
pp. 101344
Author(s):  
Farhad Banoori ◽  
Jinglun Shi ◽  
Khalid Khan ◽  
Ruiyan Han ◽  
Muhammad Irfan
Keyword(s):  
Massive Mimo ◽  
Pilot Contamination ◽  
Pilot Allocation ◽  
Allocation Strategies
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