Energy-efficient Integrated Sensing and Communication System and DNLFM Waveform

TL;DR

This paper introduces an energy-efficient integrated sensing and communication system using DNLFM waveforms with matched windows, significantly reducing power consumption and sidelobes in 6G applications.

Contribution

It proposes a novel DNLFM waveform with time-frequency matched windows and spatial-domain matched windowing to enhance energy efficiency and reduce sidelobes in ISAC systems.

Findings

Higher energy efficiency compared to conventional methods

Reduced sidelobes in sensing signals

Simplified DNLFM generation with fewer Newton iterations

Abstract

Integrated sensing and communication (ISAC) is a key enabler of 6G. Unlike communication radio links, the sensing signal requires to experience round trips from many scatters. Therefore, sensing is more power-sensitive and faces a severer multi-target interference. In this paper, the ISAC system employs dedicated sensing signals, which can be reused as the communication reference signal. This paper proposes to add time-frequency matched windows at both the transmitting and receiving sides, which avoids mismatch loss and increases energy efficiency. Discrete non-linear frequency modulation (DNLFM) is further proposed to achieve both time-domain constant modulus and frequency-domain arbitrary windowing weights. DNLFM uses very few Newton iterations and a simple geometrically-equivalent method to generate, which greatly reduces the complex numerical integral in the conventional method. Moreover, the spatial-domain matched window is proposed to achieve low sidelobes. The simulation results show that the proposed methods gain a higher energy efficiency than conventional methods.