Integrated Sensing and Communication with Nested Array: Beam Pattern and Performance Analysis

TL;DR

This paper analyzes the use of nested arrays in integrated sensing and communication systems for 6G, demonstrating improved performance and beam pattern characteristics without increasing hardware costs.

Contribution

It provides the first detailed beam pattern analysis and closed-form expressions for nested arrays in ISAC, highlighting their advantages over traditional uniform arrays.

Findings

Nested arrays achieve higher communication performance for dense user environments.

Closed-form expressions for main lobe width, peak-to-minimum ratio, and side lobe height are derived.

Simulation results confirm nested arrays' effectiveness in balancing sensing and communication.

Abstract

Towards the upcoming 6G wireless networks, integrated sensing and communication (ISAC) has been identified as one of the typical usage scenarios. To further enhance the performance of ISAC, increasing the number of antennas as well as array aperture is one of the effective approaches. However, simply increasing the number of antennas will increase the cost of radio frequency chains and power consumption. To address this issue, in this paper, we consider an uplink ISAC system with nested array deployed at the base station. Nested array is a classic sparse array architecture that is able to enlarge the array aperture without increasing the number of physical antennas. While nested array for wireless sensing has been extensively studied, its potential for ISAC system has not been fully exploited. To fill this gap, in this paper, we provide the beam pattern analysis of nested arrays, and derive the closed-form expressions for the three beam pattern metrics, namely, the main lobe beam width, peak-to-local-minimum ratio, and prominent side lobes height. Extensive simulation results are provided to show that compared with conventional uniform arrays, nested arrays can achieve higher communication performance for densely located users while maintaining its advantage of sensing.