Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems
This paper considers a multiuser broadband uplink massive multiple input multiple output (MIMO) millimeter-wave (mmWave) system. The constant envelope orthogonal frequency division multiplexing (CE-OFDM) is adopted as a modulation technique to allow an efficient power amplification, fundamental for...
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MDPI AG
2019-08-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/9/16/3363 |
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| author | Roberto Magueta Sara Teodoro Daniel Castanheira Adão Silva Rui Dinis Atílio Gameiro |
| author_facet | Roberto Magueta Sara Teodoro Daniel Castanheira Adão Silva Rui Dinis Atílio Gameiro |
| author_sort | Roberto Magueta |
| collection | DOAJ |
| description | This paper considers a multiuser broadband uplink massive multiple input multiple output (MIMO) millimeter-wave (mmWave) system. The constant envelope orthogonal frequency division multiplexing (CE-OFDM) is adopted as a modulation technique to allow an efficient power amplification, fundamental for mmWave based systems. Furthermore, a hybrid architecture is considered at the user terminals (UTs) and base station (BS) to reduce the high cost and power consumption required by a full-digital architecture, which has a radio frequency (RF) chain per antenna. Both the design of the UT’s precoder and base station equalizer are considered in this work. With the aim of maximizing the beamforming gain between each UT and the BS, the precoder analog coefficients are computed as a function of the average angles of departure (AoD), which are assumed to be known at the UTs. At the BS, the analog part is derived by assuming a system with no multi-user interference. Then, a per carrier basis nonlinear/iterative multi-user equalizer, based on the iterative block decision feedback equalization (IB-DFE) principle is designed, to explicitly remove both the multi-user and residual inter carrier interferences, not tackled in the analog part. The equalizer design metric is the sum of the mean square error (MSE) of all subcarriers, whose minimization is shown to be equivalent to the minimization of a weighted error between the hybrid and the full digital equalizer matrices. The results show that the proposed hybrid multi-user equalizer has a performance close to the fully digital counterpart. |
| first_indexed | 2024-12-14T15:10:34Z |
| format | Article |
| id | doaj.art-131f4bb854a24a338f83403671e2be10 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-14T15:10:34Z |
| publishDate | 2019-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-131f4bb854a24a338f83403671e2be102022-12-21T22:56:35ZengMDPI AGApplied Sciences2076-34172019-08-01916336310.3390/app9163363app9163363Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM SystemsRoberto Magueta0Sara Teodoro1Daniel Castanheira2Adão Silva3Rui Dinis4Atílio Gameiro5Instituto de Telecomunicações (IT) and Departamento de Eletrónica, Telecomunicações e Informática (DETI), University of Aveiro, 3810-193 Aveiro, PortugalInstituto de Telecomunicações (IT) and Departamento de Eletrónica, Telecomunicações e Informática (DETI), University of Aveiro, 3810-193 Aveiro, PortugalInstituto de Telecomunicações (IT) and Departamento de Eletrónica, Telecomunicações e Informática (DETI), University of Aveiro, 3810-193 Aveiro, PortugalInstituto de Telecomunicações (IT) and Departamento de Eletrónica, Telecomunicações e Informática (DETI), University of Aveiro, 3810-193 Aveiro, PortugalInstituto de Telecomunicações (IT) and Faculdade de Ciências e Tecnologia, University Nova de Lisboa, 1099-085 Lisboa, PortugalInstituto de Telecomunicações (IT) and Departamento de Eletrónica, Telecomunicações e Informática (DETI), University of Aveiro, 3810-193 Aveiro, PortugalThis paper considers a multiuser broadband uplink massive multiple input multiple output (MIMO) millimeter-wave (mmWave) system. The constant envelope orthogonal frequency division multiplexing (CE-OFDM) is adopted as a modulation technique to allow an efficient power amplification, fundamental for mmWave based systems. Furthermore, a hybrid architecture is considered at the user terminals (UTs) and base station (BS) to reduce the high cost and power consumption required by a full-digital architecture, which has a radio frequency (RF) chain per antenna. Both the design of the UT’s precoder and base station equalizer are considered in this work. With the aim of maximizing the beamforming gain between each UT and the BS, the precoder analog coefficients are computed as a function of the average angles of departure (AoD), which are assumed to be known at the UTs. At the BS, the analog part is derived by assuming a system with no multi-user interference. Then, a per carrier basis nonlinear/iterative multi-user equalizer, based on the iterative block decision feedback equalization (IB-DFE) principle is designed, to explicitly remove both the multi-user and residual inter carrier interferences, not tackled in the analog part. The equalizer design metric is the sum of the mean square error (MSE) of all subcarriers, whose minimization is shown to be equivalent to the minimization of a weighted error between the hybrid and the full digital equalizer matrices. The results show that the proposed hybrid multi-user equalizer has a performance close to the fully digital counterpart.https://www.mdpi.com/2076-3417/9/16/3363CE-OFDMhybrid analog/digital architecturesmassive MIMOmmWave communicationsnonlinear equalizer |
| spellingShingle | Roberto Magueta Sara Teodoro Daniel Castanheira Adão Silva Rui Dinis Atílio Gameiro Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems Applied Sciences CE-OFDM hybrid analog/digital architectures massive MIMO mmWave communications nonlinear equalizer |
| title | Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems |
| title_full | Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems |
| title_fullStr | Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems |
| title_full_unstemmed | Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems |
| title_short | Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems |
| title_sort | multiuser equalizer for hybrid massive mimo mmwave ce ofdm systems |
| topic | CE-OFDM hybrid analog/digital architectures massive MIMO mmWave communications nonlinear equalizer |
| url | https://www.mdpi.com/2076-3417/9/16/3363 |
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