Experimental demonstration of 16 Gbit/s millimeter-wave communications using MIMO processing of 2 OAM modes on each of two transmitter/receiver antenna apertures

This paper reports an experimental demonstration of a 16 Gbit/s millimeter-wave communication link using MIMO processing of 2 OAM modes on each of two transmitter/receiver antenna apertures. Two groups of multiplexed OAM beams, each containing OAM beams of ℓ =1 and +3 are generated and transmitted through two transmitter apertures respectively. The two transmitter apertures are separated with a certain distance such that the two groups of OAM beams are spatially overlapping at the receiver aperture plane. Each channel carries 1-GBaud 16-QAM signals at the same carrier frequency of 28 GHz. Our experimental results show that MIMO equalization processing can help mitigate the interferences from the other OAM channels and the BER performance of each channel improves significantly after MIMO processing. Our results indicate that OAM multiplexing and traditional spatial multiplexing combined with MIMO processing can be compatible and complementary with each other.

I. Introduction

The orthogonality of a group of wave propagation modes could be used in a line-of-sight (LoS) communication system to increase the transmitted data rates. Different from traditional spatial multiplexing system, such a system uses multiple co-axially propagating, spatially-overlapped modes, each of which carries an independent data channel. Therefore, the total capacity and spectral efficiency of the communication system can be increased. The orthogonality of the data-carrying modes allows efficient multiplexing and demultiplexing of each data channels [1], [2].