Multiplexing of OFDM-Based Radar Networks

Radar networks offer the opportunity of enhancing the radar sensing performance beyond the inherent limitations of single multiple-input multiple-output (MIMO) radars. Different locations of the individual sensor nodes allow for diverse observation angles on the targets. Moreover, in case of a coherent network, such as radar-repeater networks, the direction of arrival (DoA) capabilities are increased. However, a crucial point in exploiting the full potential of a sensor network is the separability of the signals originating from the different sensor nodes during operation, while preserving reasonable radar sensing performance of the individual sensors and the network. In this paper multiplexing methods for an orthogonal frequency-division multiplexing (OFDM)-based radar network are proposed and investigated. The first method combines traditional time and frequency multiplexing, while the second method applies a random assignment in combination with a compressed sensing-based signal evaluation. Both methods are compared with the traditional FDM multiplexing for MIMO-OFDM. For this purpose, performance criteria are proposed and the concepts are evaluated based on measurements and simulations.