Optimal finite alphabet scheme for NOMA uplink channels
Abstract The design of an optimal non‐orthogonal multiple access (NOMA) transmission scheme with finite alphabet inputs for a typical two‐user uplink wireless communication system is investigated in which each terminal is equipped with a single antenna. Each of the two users utilises a four quadratu...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-03-01
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| Series: | IET Communications |
| Subjects: | |
| Online Access: | https://doi.org/10.1049/cmu2.12564 |
| _version_ | 1811154959641608192 |
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| author | Jina Zhen Anzhong Wong Kon Max Wong Shouyi Yang Jiankang Zhang |
| author_facet | Jina Zhen Anzhong Wong Kon Max Wong Shouyi Yang Jiankang Zhang |
| author_sort | Jina Zhen |
| collection | DOAJ |
| description | Abstract The design of an optimal non‐orthogonal multiple access (NOMA) transmission scheme with finite alphabet inputs for a typical two‐user uplink wireless communication system is investigated in which each terminal is equipped with a single antenna. Each of the two users utilises a four quadrature amplitude modulation (4‐QAM) constellation to transmit information data to a common base station, and the receiver employs a maximum likelihood (ML) detector to jointly estimate both transmitted signals. Assuming the availability of channel state information at both the transmitters and the receiver, it is aimed to design a pair of scalar beamformers for the two users such that the minimum Euclidean distance between elements of the received sum‐constellation is maximised subject to the power constraints on the users. A thorough consideration of all the different conditions results in the derivation of a closed‐form optimal beamformer design. As well, examination of the construction of sum‐constellation resulted from the optimum design directly leads to the unique decoding of the original transmitted signal of each user. To facilitate practical implementation, a fast decoding procedure of the optimum NOMA scheme is further developed. The corresponding theoretic probability of ML detection error is also derived. The theoretical development of an optimum sum‐constellation for the basic 2‐user 4‐QAM system provides a solid platform for the derivation of an optimum sum‐constellation for a K‐user and/or M‐QAM system. Indeed, a simple development of the basic sum‐constellation map facilitates such extensions. Numerical simulations not only demonstrate that the performance of the fast decoder agrees closely with the theoretical analysis, but also verify that it is superior in performance to other existing NOMA designs for the same system under high signal‐to‐noise ratio. |
| first_indexed | 2024-04-10T04:25:55Z |
| format | Article |
| id | doaj.art-3a2fc59745ad49adb89fc29071e3de1e |
| institution | Directory Open Access Journal |
| issn | 1751-8628 1751-8636 |
| language | English |
| last_indexed | 2024-04-10T04:25:55Z |
| publishDate | 2023-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | IET Communications |
| spelling | doaj.art-3a2fc59745ad49adb89fc29071e3de1e2023-03-10T14:37:12ZengWileyIET Communications1751-86281751-86362023-03-0117557659010.1049/cmu2.12564Optimal finite alphabet scheme for NOMA uplink channelsJina Zhen0Anzhong Wong1Kon Max Wong2Shouyi Yang3Jiankang Zhang4School of Information Engineering Zhengzhou University Zhengzhou ChinaRBC Capital Markets Toronto Ontario CanadaSchool of Information Engineering Zhengzhou University Zhengzhou ChinaSchool of Information Engineering Zhengzhou University Zhengzhou ChinaDepartment of Electrical and Computer Engineering McMaster University Hamilton Ontario CanadaAbstract The design of an optimal non‐orthogonal multiple access (NOMA) transmission scheme with finite alphabet inputs for a typical two‐user uplink wireless communication system is investigated in which each terminal is equipped with a single antenna. Each of the two users utilises a four quadrature amplitude modulation (4‐QAM) constellation to transmit information data to a common base station, and the receiver employs a maximum likelihood (ML) detector to jointly estimate both transmitted signals. Assuming the availability of channel state information at both the transmitters and the receiver, it is aimed to design a pair of scalar beamformers for the two users such that the minimum Euclidean distance between elements of the received sum‐constellation is maximised subject to the power constraints on the users. A thorough consideration of all the different conditions results in the derivation of a closed‐form optimal beamformer design. As well, examination of the construction of sum‐constellation resulted from the optimum design directly leads to the unique decoding of the original transmitted signal of each user. To facilitate practical implementation, a fast decoding procedure of the optimum NOMA scheme is further developed. The corresponding theoretic probability of ML detection error is also derived. The theoretical development of an optimum sum‐constellation for the basic 2‐user 4‐QAM system provides a solid platform for the derivation of an optimum sum‐constellation for a K‐user and/or M‐QAM system. Indeed, a simple development of the basic sum‐constellation map facilitates such extensions. Numerical simulations not only demonstrate that the performance of the fast decoder agrees closely with the theoretical analysis, but also verify that it is superior in performance to other existing NOMA designs for the same system under high signal‐to‐noise ratio.https://doi.org/10.1049/cmu2.125645G mobile communicationmaximum likelihood detectionmultiuser detectionoptimisationprecoding |
| spellingShingle | Jina Zhen Anzhong Wong Kon Max Wong Shouyi Yang Jiankang Zhang Optimal finite alphabet scheme for NOMA uplink channels IET Communications 5G mobile communication maximum likelihood detection multiuser detection optimisation precoding |
| title | Optimal finite alphabet scheme for NOMA uplink channels |
| title_full | Optimal finite alphabet scheme for NOMA uplink channels |
| title_fullStr | Optimal finite alphabet scheme for NOMA uplink channels |
| title_full_unstemmed | Optimal finite alphabet scheme for NOMA uplink channels |
| title_short | Optimal finite alphabet scheme for NOMA uplink channels |
| title_sort | optimal finite alphabet scheme for noma uplink channels |
| topic | 5G mobile communication maximum likelihood detection multiuser detection optimisation precoding |
| url | https://doi.org/10.1049/cmu2.12564 |
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