Demonstration of interference cancellation in a multiple-user access OFDM MIMO Radar-Communication network using USRPs

Abstract

It is well known that OFDM-based systems are susceptible and weak towards subcarrier misalignment, which can lead to erroneous demodulation of the receive signal. In the usage of OFDM Radar-Communication systems, whether within cooperative or non-cooperative networks, non-overlapping subcarriers are assigned to all RadCom nodes in the vicinity. Even so OFDM subcarrier misalignment can still arise from Doppler and hardware carrier frequency offset, which lead to inter-system interference. Particularly for radar applications, the goal of interference cancellation is not only to recover the payload data correctly, but also to enable a reliable radar estimation. This paper presents a measurement verification of an inter-system OFDM-based MIMO RadCom system interference cancellation concept for use in a multiple-user access environment at a scaled-down carrier frequency using universal software radio peripherals (USRPs).