Experimental Demonstration of a Low-complexity Multiple-input Single-output Frequency Diverse Array Framework

Spatially diverse transmissions provide spatial selectivity via a fast-time modulation structure that changes with angle. This property provides the ability to spatially beamform on receive via signal separation according to the well-known virtual array. Therefore, a single channel receiver can be used in a Multiple-Input Single-Output (MISO) configuration to provide delay, Doppler, and angular information of scatterers illuminated with this type of transmission. Here, we experimentally demonstrate a MISO concept with a linear frequency modulated continuous-wave frequency diverse array (LFMCW-FDA) framework. This transmission is investigated for its ease of implementation, its applicability to standard receive signal processing, and benefits regarding the usable unambiguous range-Doppler space compared to other spatially diverse transmissions (i.e., Doppler-division and time-division). The experimental results show that, as predicted, the MISO virtual aperture for the LFMCW-FDA transmission appears in the delay dimension after correlation filtering and contains the spatial information of the scatterer.