Abstract
Propagation of electromagnetic waves with orbital angular momentum (OAM) is investigated in indoor environments. The OAM modes generated by circular patch array antennas are used. With proper alignment and suppressed multipath, the OAM modes can transport multiple wireless data stream at the same time. Through measurements and ray-tracing simulations, it is found that the advantages of OAM modes are limited if those two conditions are not satisfied. It is also found that multipath effect can be enervated by using narrow beam antennas.
Highlights
As the demand for high data rate wireless communication increases, various modulation schemes are devised in the frequency, time, and spatial domains like OFDM, TDMA, SDMA, and MIMO
Orbital angular momentum (OAM) of electromagnetic waves receives interest in that it can increase the capacity of wireless communications
For the case of spherical or cylindrical coordinate, the orbital angular momentums are associated with eigenvalue for the elevation or azimuth angles
Summary
As the demand for high data rate wireless communication increases, various modulation schemes are devised in the frequency, time, and spatial domains like OFDM, TDMA, SDMA, and MIMO. Along with those approaches, orbital angular momentum (OAM) of electromagnetic waves receives interest in that it can increase the capacity of wireless communications. It was found that the same Laguerre-Gaussian modes can be generated at the microwave frequency using the same phase plate and a circular corrugated horn antenna [3]. It is shown that the capacity increase of OAM waves is limited by interference incurred by multipath fading, which is even aggravated with wide beam width antennas. By changing the beam width of element antennas, the condition for large indoor coverage is derived
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
