Broadband beam steering for misaligned multi-mode OAM communication systems

• 作者: TIAN Zhengjuan CHEN Rui LONG Wenxuan ZHOU Hong MORETTI Marco
• 来源期刊: 系统工程与电子技术（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: SENSOR ARRAY SIGNAL PROCESSING AND ITS APPLICATIONS IN 5G/6G
• 页码范围: 779-788
• 页数: 10页
• 语种: 英文
• DOI: 10.23919/JSEE.2021.000067

摘要

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 fre-quency channel to achieve high spectral efficiency (SE). However, the precondition for maintaining the orthogonality among different OAM modes is perfect alignment of the trans-mit 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 ob-lique 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 di-gital transceiver structures and corresponding beam steering schemes. Mathematical analysis and numerical simulations vali-date 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 ele-ments are large, which validates that the baseband digital trans-ceiver with DBS is more suitable for multi-mode OAM broad-band wireless communication systems in practice.