Highly Efficient Waveform Design and Hybrid Duplex for Joint Communication and Sensing

TL;DR

This paper introduces a novel waveform design called MaRS for joint communication and sensing in 6G, achieving high resolution with minimal resource usage, and proposes a hybrid duplex scheme to enhance sensing performance.

Contribution

It presents the MaRS waveform design for efficient radar sensing within OFDM systems and a hybrid duplex scheme combining half- and full-duplex for improved sensing resolution.

Findings

MaRS achieves large time-frequency aperture with minimal resource consumption.

Hybrid duplex scheme enhances sensing resolution using combined antenna arrays.

Proposed methods significantly reduce resource overheads compared to traditional approaches.

Abstract

Joint communication and sensing (JCAS) is a very promising 6G technology, which attracts more and more research attention. Compared with communication, radar has many unique features in terms of waveform design criteria, self-interference cancellation (SIC), aperture-dependent resolution, and virtual aperture. This paper proposes a novel waveform design named max-aperture radar slicing (MaRS) to gain a large time-frequency aperture, which is generated by orthogonal frequency division multiplexing (OFDM) and occupies only a tiny fraction of OFDM resources. The proposed MaRS keeps the radar advantages of constant modulus, zero auto-correlation sequence, and simple SIC. As MaRS consumes much less resources, conventional processing methods fail, and novel angle-Doppler map based methods are proposed to obtain the range-velocity-angle information from MaRS echos and strong clutters. To avoid complex full-duplex communication, this paper proposes a hybrid-duplex JCAS scheme composed of half-duplex communication and full-duplex radar. The half-duplex communication antenna array is reused, and a small sensing-dedicated antenna array is added. Using these two arrays, a large space-domain sensing aperture is virtually formed to greatly improve the angle resolution. The numerical results show that the proposed MaRS and hybrid duplex can achieve a high sensing resolution with only 0.4% OFDM resources, which reduces the overheads of conventional methods to less than one tenth.