Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems
Abstract In this paper, the cell-free massive multiple input multiple output (MIMO) network is affected by the pilot contamination phenomenon when a large number of users and a small number of available pilots exists, the quality of service (QoS) will deteriorate due to the low accuracy of the chann...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2022-10-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-21241-0 |
| _version_ | 1828343934890278912 |
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| author | Abdulrahman Al Ayidh Yusuf Sambo Muhammad Ali Imran |
| author_facet | Abdulrahman Al Ayidh Yusuf Sambo Muhammad Ali Imran |
| author_sort | Abdulrahman Al Ayidh |
| collection | DOAJ |
| description | Abstract In this paper, the cell-free massive multiple input multiple output (MIMO) network is affected by the pilot contamination phenomenon when a large number of users and a small number of available pilots exists, the quality of service (QoS) will deteriorate due to the low accuracy of the channel estimation because some of users will use the same pilot. Therefore, we address this problem by presenting two novel schemes of pilot assignment and pilot power control design based on the matching technique for the uplink of cell-free massive MIMO systems to maximize spectral efficiency. We first formulate an assignment optimization problem in order to find the best possible pilot sequence to be used by utilizing genetic algorithm (GA) and then propose a Hungarian matching algorithm to solve this formulated problem. Regarding the power control design, we formulate a minimum-weighted assignment problem to assign pilot power control coefficients to the estimated channel’s minimum mean-squared error by considering the access point (AP) selection. Then, we also propose the Hungarian algorithm to solve this problem. Simulation results show that our proposed schemes outperform the state-of-the-art techniques concerning both the pilot assignment and the pilot power control design by achieving a 15% improvement in the spectral efficiency. Finally, the computational complexity analysis is provided for the proposed schemes compared with the state-of-the-art techniques. |
| first_indexed | 2024-04-13T23:50:02Z |
| format | Article |
| id | doaj.art-8a3eb17fd4eb42a19187749547792b82 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-13T23:50:02Z |
| publishDate | 2022-10-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-8a3eb17fd4eb42a19187749547792b822022-12-22T02:24:09ZengNature PortfolioScientific Reports2045-23222022-10-0112111410.1038/s41598-022-21241-0Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systemsAbdulrahman Al Ayidh0Yusuf Sambo1Muhammad Ali Imran2School of Engineering, University of GlasgowSchool of Engineering, University of GlasgowSchool of Engineering, University of GlasgowAbstract In this paper, the cell-free massive multiple input multiple output (MIMO) network is affected by the pilot contamination phenomenon when a large number of users and a small number of available pilots exists, the quality of service (QoS) will deteriorate due to the low accuracy of the channel estimation because some of users will use the same pilot. Therefore, we address this problem by presenting two novel schemes of pilot assignment and pilot power control design based on the matching technique for the uplink of cell-free massive MIMO systems to maximize spectral efficiency. We first formulate an assignment optimization problem in order to find the best possible pilot sequence to be used by utilizing genetic algorithm (GA) and then propose a Hungarian matching algorithm to solve this formulated problem. Regarding the power control design, we formulate a minimum-weighted assignment problem to assign pilot power control coefficients to the estimated channel’s minimum mean-squared error by considering the access point (AP) selection. Then, we also propose the Hungarian algorithm to solve this problem. Simulation results show that our proposed schemes outperform the state-of-the-art techniques concerning both the pilot assignment and the pilot power control design by achieving a 15% improvement in the spectral efficiency. Finally, the computational complexity analysis is provided for the proposed schemes compared with the state-of-the-art techniques.https://doi.org/10.1038/s41598-022-21241-0 |
| spellingShingle | Abdulrahman Al Ayidh Yusuf Sambo Muhammad Ali Imran Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems Scientific Reports |
| title | Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems |
| title_full | Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems |
| title_fullStr | Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems |
| title_full_unstemmed | Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems |
| title_short | Mitigation pilot contamination based on matching technique for uplink cell-free massive MIMO systems |
| title_sort | mitigation pilot contamination based on matching technique for uplink cell free massive mimo systems |
| url | https://doi.org/10.1038/s41598-022-21241-0 |
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