Orthogonal Coexistence of Overlapped Radar and Communication Waveforms

Abstract

With revolutionary new services and applications, integrated sensing and communication has been essential for recent and future wireless communication systems. For the communication systems, the cyclic prefix - orthogonal frequency division multiplexing (CP-OFDM) is a widely used waveform in various wireless standards due to its high spectral efficiency and resilience to static multi-path channel conditions. On the other hand, the frequency modulated continuous-wave (FMCW) is a popular waveform in radar-sensing applications, especially for autonomous vehicles. Although communication signals over the air are utilized for sensing applications, such as passive radars, however, these systems have limited sensing capabilities. Also, several coexistence schemes are introduced for these different systems, communication and radar-sensing that separately allocate time, frequency and space resources. Unlike these approaches, a novel waveform design by overlapping on the same time and frequency resources is proposed to provide orthogonal coexistence for joint radar and communication (JRC) systems. For the proposed design, the channel estimation and bit-error rate (BER) performances are compared with the conventional CP-OFDM systems, and it is demonstrated that the same performance can be obtained in the proposed coexistence. Therefore, this waveform design due to the overlapping achieves a better spectral efficiency compared to separate resource sharing approaches.