Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks
With the development of the next generation of mobile networks, new research challenges have emerged, and new technologies have been proposed to address them. On the other hand, reconfigurable intelligent surface (RIS) technology is being investigated for partially controlling wireless channels. RIS...
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| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Technologies |
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| Online Access: | https://www.mdpi.com/2227-7080/11/3/73 |
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| author | Abdel Nasser Soumana Hamadou Ciira wa Maina Moussa Moindze Soidridine |
| author_facet | Abdel Nasser Soumana Hamadou Ciira wa Maina Moussa Moindze Soidridine |
| author_sort | Abdel Nasser Soumana Hamadou |
| collection | DOAJ |
| description | With the development of the next generation of mobile networks, new research challenges have emerged, and new technologies have been proposed to address them. On the other hand, reconfigurable intelligent surface (RIS) technology is being investigated for partially controlling wireless channels. RIS is a promising technology for improving signal quality by controlling the scattering of electromagnetic waves in a nearly passive manner. Heterogeneous networks (HetNets) are another promising technology that is designed to meet the capacity requirements of the network. RIS technology can be used to improve system performance in the context of HetNets. This study investigates the applications of reconfigurable intelligent surfaces (RISs) in heterogeneous downlink networks (HetNets). Due to the network densification, the small cell base station (SBS) interferes with the macrocell users (MUEs). In this paper, we utilise RIS to mitigate cross-tier interference in a HetNet via directional beamforming by adjusting the phase shift of the RIS. We consider RIS-assisted heterogeneous networks consisting of multiple SBS nodes and MUEs that utilise both direct paths and reflected paths. Therefore, the aim of this study is to maximise the sum rate of all MUEs by jointly optimising the transmit beamforming of the macrocell base station (MBS) and the phase shift of the RIS. An efficient RIS reflecting coefficient-based optimisation (RCO) is proposed based on a successive convex approximation approach. Simulation results are provided to show the effectiveness of the proposed scheme in terms of its sum rate in comparison with the scheme HetNet without RIS and the scheme HetNet with RIS but with random phase shifts. |
| first_indexed | 2024-03-11T01:52:31Z |
| format | Article |
| id | doaj.art-d2846660e65c4dfdba85011fac68a2d1 |
| institution | Directory Open Access Journal |
| issn | 2227-7080 |
| language | English |
| last_indexed | 2024-03-11T01:52:31Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Technologies |
| spelling | doaj.art-d2846660e65c4dfdba85011fac68a2d12023-11-18T12:53:07ZengMDPI AGTechnologies2227-70802023-06-011137310.3390/technologies11030073Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous NetworksAbdel Nasser Soumana Hamadou0Ciira wa Maina1Moussa Moindze Soidridine2Department of Electrical Engineering, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi P.O. Box 62000-00200, KenyaCentre for Data Science and Artificial Intelligence (DSAIL), Dedan Kimathi University of Technology (DeKUT), Nyeri P.O. Box 657-10100, KenyaFaculty of Science and Techniques, University of Comoros, Moroni, ComorosWith the development of the next generation of mobile networks, new research challenges have emerged, and new technologies have been proposed to address them. On the other hand, reconfigurable intelligent surface (RIS) technology is being investigated for partially controlling wireless channels. RIS is a promising technology for improving signal quality by controlling the scattering of electromagnetic waves in a nearly passive manner. Heterogeneous networks (HetNets) are another promising technology that is designed to meet the capacity requirements of the network. RIS technology can be used to improve system performance in the context of HetNets. This study investigates the applications of reconfigurable intelligent surfaces (RISs) in heterogeneous downlink networks (HetNets). Due to the network densification, the small cell base station (SBS) interferes with the macrocell users (MUEs). In this paper, we utilise RIS to mitigate cross-tier interference in a HetNet via directional beamforming by adjusting the phase shift of the RIS. We consider RIS-assisted heterogeneous networks consisting of multiple SBS nodes and MUEs that utilise both direct paths and reflected paths. Therefore, the aim of this study is to maximise the sum rate of all MUEs by jointly optimising the transmit beamforming of the macrocell base station (MBS) and the phase shift of the RIS. An efficient RIS reflecting coefficient-based optimisation (RCO) is proposed based on a successive convex approximation approach. Simulation results are provided to show the effectiveness of the proposed scheme in terms of its sum rate in comparison with the scheme HetNet without RIS and the scheme HetNet with RIS but with random phase shifts.https://www.mdpi.com/2227-7080/11/3/73RISHetNetspectral efficiencycross-tier interferenceoptimisationMIMO |
| spellingShingle | Abdel Nasser Soumana Hamadou Ciira wa Maina Moussa Moindze Soidridine Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks Technologies RIS HetNet spectral efficiency cross-tier interference optimisation MIMO |
| title | Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks |
| title_full | Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks |
| title_fullStr | Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks |
| title_full_unstemmed | Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks |
| title_short | Cross-Tier Interference Mitigation for RIS-Assisted Heterogeneous Networks |
| title_sort | cross tier interference mitigation for ris assisted heterogeneous networks |
| topic | RIS HetNet spectral efficiency cross-tier interference optimisation MIMO |
| url | https://www.mdpi.com/2227-7080/11/3/73 |
| work_keys_str_mv | AT abdelnassersoumanahamadou crosstierinterferencemitigationforrisassistedheterogeneousnetworks AT ciirawamaina crosstierinterferencemitigationforrisassistedheterogeneousnetworks AT moussamoindzesoidridine crosstierinterferencemitigationforrisassistedheterogeneousnetworks |