Multi-functional Coexistence of Radar-Sensing and Communication Waveforms

TL;DR

This paper introduces a novel joint radar-sensing and communication waveform scheme that superimposes FMCW and OFDM signals, enabling simultaneous operation with minimal performance trade-offs.

Contribution

It proposes a non-orthogonal superimposition of FMCW and OFDM waveforms and a receiver scheme for channel estimation that preserves data rate and sensing accuracy.

Findings

Achieves good sensing accuracy at low SNR

Communication performance is only 0.6 dB below ideal conditions at 1% BER

Effective joint operation without significant performance loss

Abstract

In this study, a novel transmission scheme is proposed to serve radar-sensing and communication objectives at the same time and allocated bandwidth. The proposed transmitted frame non-orthogonally superimposes two different waveforms, which are frequency modulated continuous-wave (FMCW) for radar-sensing and orthogonal frequency division multiplexing (OFDM) for communication. Also, the receiver scheme that performs channel estimation via radar-sensing functionality without degrading data rate of communication operation is introduced. As numerically evaluated, the proposed system achieves good sensing accuracy even if the signal-to-noise ratio (SNR) is low, and communication performance is only 0.6 dB less at the target bit-error rate (BER) of 1% compared to the assumption of perfect channel state information (CSI) without any pilot overhead over OFDM subcarriers.