28 GHz Over-the-Air Measurement using an OTFS Multi-User Distributed MIMO

Abstract

This paper describes the experimental investigation of orthogonal time frequency space (OTFS) modulation using a 28 GHz multi-user distributed multiple-input multiple-output (D-MIMO) testbed in over-the-air (OTA) and mobility environments. We build the D-MIMO testbed in an actual office floor, and measure OTFS signals and orthogonal frequency-division multiplexing (OFDM) signals with up to four user simultaneous connections. OTFS indicates higher robustness in time-variant channels than OFDM. The error vector magnitude (EVM) and system throughput of OTFS are −22 dB and 1.9 Gbps with 100 MHz signal bandwidth, respectively. In our knowledge, this is a first paper describing the OTA measurements of EVM, throughput, and spectral efficiency using OTFS modulation on the 28 GHz coherent beamforming system.