Journal of Systems Engineering and Electronics ›› 2021, Vol. 32 ›› Issue (4): 779-788.doi: 10.23919/JSEE.2021.000067

• SENSOR ARRAY SIGNAL PROCESSING AND ITS APPLICATIONS IN 5G/6G • Previous Articles     Next Articles

Broadband beam steering for misaligned multi-mode OAM communication systems

Zhengjuan TIAN1(), Rui CHEN1,*(), Wenxuan LONG1,2(), Hong ZHOU1(), Marco MORETTI2()   

  1. 1 School of Communication Engineering, Xidian University, Xi’an 710071, China
    2 Department of Information Engineering, University of Pisa, Pisa 56126, Italy
  • Received:2020-11-20 Online:2021-08-18 Published:2021-09-30
  • Contact: Rui CHEN E-mail:zjtian@stu.xidian.edu.cn;rchen@xidian.edu.cn;wxlong@stu.xidian.edu.cn;hzhou_1@stu.xidian.edu.cn;marco.moretti@iet.unipi.it
  • About author:|TIAN Zhengjuan was born in 1993. She received her B.S. degree in communications engineering from Shanghai University, Shanghai, China in 2018 and M.S. degree in electronic and communication engineering from Xidian University, Xi’an, China in 2021. Her research interests include orbital angular momentum communication systems and array signal processing. E-mail: zjtian@stu.xidian.edu.cn||CHEN Rui was born in 1983. He received his B.S., M.S., and Ph.D. degrees in communications and information systems from Xidian University, Xi’an, China, in 2005, 2007 and 2011, respectively. From 2014 to 2015, he was a visiting scholar at Columbia University in the City of New York. He is currently an associate professor and Ph.D. supervisor in the School of Telecommunications Engineering at Xidian University. His research interests include broadband wireless communication systems, array signal processing, and intelligent transportation systems. E-mail: rchen@xidian.edu.cn||LONG Wenxuan was born in 1994. She received her B.S. degree in rail transit signal and control from Dalian Jiaotong University, Dalian, China in 2017. She is currently pursuing a double Ph.D. degree in communications and information systems at Xidian University, China, and University of Pisa, Italy. Her research interests include broadband wireless communication systems and array signal processing. E-mail: wxlong@stu.xidian.edu.cn||ZHOU Hong was born in 1996. She received her B.S. degree in communications engineering from Hefei University of Technology, Hefei, China in 2018 and M.S. degree in communications and information systems from Xidian University, Xi’an, China in 2021. Her research interests include orbital angular momentum communication systems and array signal processing. E-mail: hzhou_1@stu.xidian.edu.cn||MORETTI Marco was born in 1970. He received his degree in electronic engineering from University of Florence, Florence, Italy, in 1995, and Ph.D. degree from Delft University of Technology, Delft, the Netherlands, in 2000. From 2000 to 2003, he was a senior researcher with Marconi Mobile. He is currently an associate professor with University of Pisa, Pisa, Italy. His research interests include resource allocation for multicarrier systems, synchronization, and channel estimation. E-mail: marco.moretti@iet.unipi.it
  • Supported by:
    This work was supported by the Natural Science Basic Research Program of Shaanxi (2021JZ-18), the Natural Science Foundation of Guangdong Province of China (2021A1515010812), the Open Research Fund of National Mobile Communications Research Laboratory, Southeast University (2021D04), the Fundamental Research Funds for Central Universities, and the Innovation Fund of Xidian University

Abstract:

Orbital angular momentum (OAM) at radio frequency (RF) has attracted more and more attention as a novel approach of multiplexing a set of orthogonal OAM modes on the same frequency channel to achieve high spectral efficiency (SE). However, the precondition for maintaining the orthogonality among different OAM modes is perfect alignment of the transmit and receive uniform circular arrays (UCAs), which is difficult to be satisfied in practical wireless communication scenarios. Therefore, to achieve available multi-mode OAM broadband wireless communication, we first investigate the effect of oblique angles on the transmission performance of the multi-mode OAM broadband system in the non-parallel misalignment case. Then, we compare the UCA-based RF analog and baseband digital transceiver structures and corresponding beam steering schemes. Mathematical analysis and numerical simulations validate that the SE of the misaligned multi-mode OAM broadband system is quite low, while analog and digital beam steering (DBS) both can significantly improve the SE of the system. However, DBS can obtain higher SE than analog beam steering especially when the bandwidth and the number of array elements are large, which validates that the baseband digital transceiver with DBS is more suitable for multi-mode OAM broadband wireless communication systems in practice.

Key words: orbital angular momentum (OAM), uniform circular array (UCA), broadband wireless communication, misalignment, beam steering