Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming
Phased antenna arrays have been used extensively for massive MIMO-based multiuser beamforming to improve both the throughput and power efficiency of wireless communication systems. Beamforming can be realized by the Butler matrix, which has been demonstrated in the electric domain. With wireless sys...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2018-01-01
|
| Series: | IEEE Photonics Journal |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/8295006/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1839645053060907008 |
|---|---|
| author | Huiyuan Liu Xiang Liu Frank Effenberger Naresh Chand Xiaofeng Qi Guifang Li |
| author_facet | Huiyuan Liu Xiang Liu Frank Effenberger Naresh Chand Xiaofeng Qi Guifang Li |
| author_sort | Huiyuan Liu |
| collection | DOAJ |
| description | Phased antenna arrays have been used extensively for massive MIMO-based multiuser beamforming to improve both the throughput and power efficiency of wireless communication systems. Beamforming can be realized by the Butler matrix, which has been demonstrated in the electric domain. With wireless systems migration toward simplified remote radio units through radio-over-fiber and sharing of signal processing functions located in the central office, it is desirable to implement this beamforming technique in the optical domain. In this paper, we propose an optical implementation of the Butler matrix using purely passive optical components such as directional couplers and delay lines. With the additional use of optical routing elements, the number of signal streams connected to the baseband unit equals the number of the actual users rather than the number of antenna elements, thereby achieving hardware efficiency for multiuser beamforming. Moreover, the proposed optical Butler matrix acts on the optical intensity rather than the optical field, and therefore, low-cost intensity-modulation direct-detection (IMDD) optical transceivers can be used. A proof-of-concept experiment is conducted to demonstrate the optical 2 × 2 Butler matrix. Scaling the optical Butler matrix to high port counts is also discussed. |
| format | Article |
| id | doaj-art-b9b10c7021de4c2ab8c559c8a05f6881 |
| institution | Matheson Library |
| issn | 1943-0655 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Photonics Journal |
| spelling | doaj-art-b9b10c7021de4c2ab8c559c8a05f68812025-07-01T23:36:30ZengIEEEIEEE Photonics Journal1943-06552018-01-011021810.1109/JPHOT.2018.28058758295006Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser BeamformingHuiyuan Liu0https://orcid.org/0000-0002-9611-9377Xiang Liu1Frank Effenberger2Naresh Chand3Xiaofeng Qi4Guifang Li5Futurewei Technologies, Huawei R&D USA, Bridgewater, NJ, USAFuturewei Technologies, Huawei R&D USA, Bridgewater, NJ, USAFuturewei Technologies, Huawei R&D USA, Bridgewater, NJ, USAFuturewei Technologies, Huawei R&D USA, Bridgewater, NJ, USAFuturewei Technologies, Huawei R&D USA, Bridgewater, NJ, USACREOL, College of Optics and Photonics, University of Central Florida, Orlando, FL, USAPhased antenna arrays have been used extensively for massive MIMO-based multiuser beamforming to improve both the throughput and power efficiency of wireless communication systems. Beamforming can be realized by the Butler matrix, which has been demonstrated in the electric domain. With wireless systems migration toward simplified remote radio units through radio-over-fiber and sharing of signal processing functions located in the central office, it is desirable to implement this beamforming technique in the optical domain. In this paper, we propose an optical implementation of the Butler matrix using purely passive optical components such as directional couplers and delay lines. With the additional use of optical routing elements, the number of signal streams connected to the baseband unit equals the number of the actual users rather than the number of antenna elements, thereby achieving hardware efficiency for multiuser beamforming. Moreover, the proposed optical Butler matrix acts on the optical intensity rather than the optical field, and therefore, low-cost intensity-modulation direct-detection (IMDD) optical transceivers can be used. A proof-of-concept experiment is conducted to demonstrate the optical 2 × 2 Butler matrix. Scaling the optical Butler matrix to high port counts is also discussed.https://ieeexplore.ieee.org/document/8295006/Microwave photonicsoptical fibersphased arraysbeam steeringButler matricesoptical interconnections |
| spellingShingle | Huiyuan Liu Xiang Liu Frank Effenberger Naresh Chand Xiaofeng Qi Guifang Li Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming IEEE Photonics Journal Microwave photonics optical fibers phased arrays beam steering Butler matrices optical interconnections |
| title | Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming |
| title_full | Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming |
| title_fullStr | Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming |
| title_full_unstemmed | Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming |
| title_short | Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming |
| title_sort | optical implementation of butler matrix for hardware efficient multiuser beamforming |
| topic | Microwave photonics optical fibers phased arrays beam steering Butler matrices optical interconnections |
| url | https://ieeexplore.ieee.org/document/8295006/ |
| work_keys_str_mv | AT huiyuanliu opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming AT xiangliu opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming AT frankeffenberger opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming AT nareshchand opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming AT xiaofengqi opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming AT guifangli opticalimplementationofbutlermatrixforhardwareefficientmultiuserbeamforming |