Radio Vortex–Multiple-Input Multiple-Output Communication Systems With High Capacity

Abstract

As a potential technique to improve channel capacity, orbital angular momentum has been developed in the radio field. In this paper, a novel radio vortex-multiple-input multiple-output (RV-MIMO) system is proposed to provide high capacity in free space. In particular, the vortex channel of the proposed system is modeled. Based on this model, the optimal vortex phase is derived, which results in the optimal capacity of the proposed RV-MIMO system. Simulation results show that the proposed RV-MIMO system could achieve higher capacity than the MIMO system in free space.INDEX TERMS Orbital angular momentum, radio vortex, multiple-input multiple-output, vortex phase.

Capacity Performance of Wireless Oam-Based Massive Mimo System

“…The transfer function from T n to R m can be considered as the MIMO response superimposed by a spiral phase term [14], and expressed as follows…”

“…As the basis for performance analysis, the channel matrix of wireless OAM-MIMO systems with various array configurations has been studied, such as the typical UCA system [14,15], misalignment UCA system [16], nested UCA system [17], fractal UCA system [18], and uniform line array (ULA) systems [19,20]. In spite of offering some inspirations, these reports do not use reference coordinates in analysis process, which is actually of significance due to the extreme spatial coordinate dependence of OAM fields.…”

Generation of Orbital Angular Momentum Radio Waves Based on Dielectric Resonator Antenna

“…Their orthogonal channels offer the possibility to improve radio transmission capacity by exploiting different OAM modes. Although this kind of transmissions could be regarded as a subset of traditional multiple-in-multiple-out (MIMO) systems, where OAM based communication provides an optimal solution only under specific conditions [1], the potential applications of OAM waves in radio systems should not be ignored [2][3][4][5], and OAM based radio links have already been demonstrated at many microwave frequencies [6][7][8][9]. On the other hand, OAM has already found useful and various applications in the optical regime [10][11][12][13], thus it is very attractive and interesting to investigate in detail OAM-carrying microwaves and extend these applications into the microwave regime.…”

Massive OAM‐MIMO transmission scheme for 5G networks and beyond

“…As the basis of channel matrix-based performance analysis, OAM-MIMO systems are so far mainly configured by UCA [29][30][31][32][33][34], uniform line array (ULA) [35][36][37][38], and uniform rectangular array (URA) [39]. System models of OAM-MIMO in the cases of line-of-sight (LoS) [40][41][42], non-LoS (NLoS) FIGURE 1 Uniform line array (ULA)-based massive orbital angular momentum and multiple-input multiple-output (OAM-MIMO) system in the multipath scene [38,43,44], alignment [29,45] and misalignment [33,34,44] were preliminarily analysed, which show many positive results about OAM-MIMO increasing the spectrum efficiency. However, UCA is often used as an OAM generator rather than a suitable OAM multiplexer in lots of existed reports, and such conduct misses the possible benefits of OAM multiplexing technology since only an OAM carrier works per time slot [32,41,45].…”