Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint
Abstract In this paper, we study the hybrid beamforming for the wideband mmWave multiuser MIMO-OFDM system. We characterize the frequency-dependent beam angle problem, i.e., beam squint effect. Firstly, we extend the mmWave channel model from the Saleh-Valenzuela representation with the consideratio...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2018-11-01
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| Series: | EURASIP Journal on Wireless Communications and Networking |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13638-018-1280-5 |
| _version_ | 1818381241108398080 |
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| author | Bin Liu Hongbo Zhu |
| author_facet | Bin Liu Hongbo Zhu |
| author_sort | Bin Liu |
| collection | DOAJ |
| description | Abstract In this paper, we study the hybrid beamforming for the wideband mmWave multiuser MIMO-OFDM system. We characterize the frequency-dependent beam angle problem, i.e., beam squint effect. Firstly, we extend the mmWave channel model from the Saleh-Valenzuela representation with the consideration of beam squint. Secondly, a two-tier hybrid beamforming is proposed to achieve the maximum spectral efficiency in wideband mmWave multiuser MIMO-OFDM system. In the first tier, the Rotman lens array is adopted as the analog precoder to provide true-time-delay (TTD) and reduce the beam squint impairment. Moreover, the first-tier baseband precoder is designed based on block diagonalization (BD) to cancel inter-user interference. We further consider the finite spatial resolution and power leakage problem of the lens array. The second-tier hybrid precoder is proposed to collect the leak power with the phase shifter array. The optimal second-tier hybrid precoder design is formulated as the matrix factorization problem, and the two-tier hybrid precoding algorithm is based on the alternative minimization. It is found that both the beam squint and frequency-selective effect should be considered in the wideband mmWave system. Simulation results show that the proposed two-tier hybrid precoder could reduce beam squint impairment and inter-user interference, and could approximate to the optimal full-digital precoder with much fewer RF chains. |
| first_indexed | 2024-12-14T02:31:27Z |
| format | Article |
| id | doaj.art-c8725fcb91a245dfad428111d11e974a |
| institution | Directory Open Access Journal |
| issn | 1687-1499 |
| language | English |
| last_indexed | 2024-12-14T02:31:27Z |
| publishDate | 2018-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | EURASIP Journal on Wireless Communications and Networking |
| spelling | doaj.art-c8725fcb91a245dfad428111d11e974a2022-12-21T23:20:15ZengSpringerOpenEURASIP Journal on Wireless Communications and Networking1687-14992018-11-012018111310.1186/s13638-018-1280-5Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squintBin Liu0Hongbo Zhu1Jiangsu Key Laboratory of Wireless Communications, Nanjing University of Posts and TelecommunicationsJiangsu Key Laboratory of Wireless Communications, Nanjing University of Posts and TelecommunicationsAbstract In this paper, we study the hybrid beamforming for the wideband mmWave multiuser MIMO-OFDM system. We characterize the frequency-dependent beam angle problem, i.e., beam squint effect. Firstly, we extend the mmWave channel model from the Saleh-Valenzuela representation with the consideration of beam squint. Secondly, a two-tier hybrid beamforming is proposed to achieve the maximum spectral efficiency in wideband mmWave multiuser MIMO-OFDM system. In the first tier, the Rotman lens array is adopted as the analog precoder to provide true-time-delay (TTD) and reduce the beam squint impairment. Moreover, the first-tier baseband precoder is designed based on block diagonalization (BD) to cancel inter-user interference. We further consider the finite spatial resolution and power leakage problem of the lens array. The second-tier hybrid precoder is proposed to collect the leak power with the phase shifter array. The optimal second-tier hybrid precoder design is formulated as the matrix factorization problem, and the two-tier hybrid precoding algorithm is based on the alternative minimization. It is found that both the beam squint and frequency-selective effect should be considered in the wideband mmWave system. Simulation results show that the proposed two-tier hybrid precoder could reduce beam squint impairment and inter-user interference, and could approximate to the optimal full-digital precoder with much fewer RF chains.http://link.springer.com/article/10.1186/s13638-018-1280-5Hybrid precodingMillimeter waveWideband systemMIMOBeam squintMultiuser interference |
| spellingShingle | Bin Liu Hongbo Zhu Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint EURASIP Journal on Wireless Communications and Networking Hybrid precoding Millimeter wave Wideband system MIMO Beam squint Multiuser interference |
| title | Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint |
| title_full | Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint |
| title_fullStr | Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint |
| title_full_unstemmed | Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint |
| title_short | Rotman lens-based two-tier hybrid beamforming for wideband mmWave MIMO-OFDM system with beam squint |
| title_sort | rotman lens based two tier hybrid beamforming for wideband mmwave mimo ofdm system with beam squint |
| topic | Hybrid precoding Millimeter wave Wideband system MIMO Beam squint Multiuser interference |
| url | http://link.springer.com/article/10.1186/s13638-018-1280-5 |
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