eprintid: 1546230 rev_number: 29 eprint_status: archive userid: 608 dir: disk0/01/54/62/30 datestamp: 2017-03-29 09:35:50 lastmod: 2021-12-13 03:13:21 status_changed: 2017-03-29 09:35:50 type: article metadata_visibility: show creators_name: Li, A creators_name: Masouros, C title: Exploiting Constructive Mutual Coupling in P2P MIMO by Analog-Digital Phase Alignment ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F46 keywords: Science & Technology, Technology, Engineering, Electrical & Electronic, Telecommunications, Engineering, MIMO, mutual coupling, constructive interference, optimization, Green Signal Power, Spatial Correlation, Precoding Scheme, Wireless Systems, Fading Channels, Performance, Interference, Compensation, Downlink, Antennas note: Copyright © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/ abstract: In this paper, we propose a joint analog-digital (A/D) beamforming scheme for the point-to-point multiple-input-multiple-output system, where we exploit mutual coupling by optimizing the load impedances of the transmit antennas. Contrary to the common conception that mutual coupling strictly harms the system performance, we show that mutual coupling can be beneficial by exploiting the concept of constructive interference. By changing the value of each load impedance for the antenna array based on convex optimization, the mutual coupling effect can be manipulated so that the resulting interference aligns constructively to the useful signal vector. We first prove that the full elimination of mutual coupling effect is not achievable solely by tuning the values of the antenna load impedances. We then introduce the proposed A/D scheme for both PSK and QAM modulations, where performance gains with respect to conventional techniques are obtained. The implementation of the proposed schemes is also discussed, where a lookup table can be built to efficiently apply the calculated load impedances. The numerical results show that the proposed schemes can achieve an improved performance compared to systems with fixed mutual coupling, especially when the antenna spacing is small. date: 2017-01-24 date_type: published publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC official_url: http://doi.org/10.1109/TWC.2017.2657631 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1276958 doi: 10.1109/TWC.2017.2657631 lyricists_name: Li, Ang lyricists_name: Masouros, Christos lyricists_id: ALIAX43 lyricists_id: CMASO14 actors_name: Masouros, Christos actors_id: CMASO14 actors_role: owner full_text_status: public publication: IEEE Transactions on Wireless Communications volume: 16 number: 3 pagerange: 1948-1962 pages: 15 issn: 1558-2248 citation: Li, A; Masouros, C; (2017) Exploiting Constructive Mutual Coupling in P2P MIMO by Analog-Digital Phase Alignment. IEEE Transactions on Wireless Communications , 16 (3) pp. 1948-1962. 10.1109/TWC.2017.2657631 <https://doi.org/10.1109/TWC.2017.2657631>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1546230/1/Masouros_Exploiting%20Mutual%20Coupling%20for%20P2P%20MIMO_vor.pdf