Target Detection Performance of Spectrum Sharing MIMO Radars

TL;DR

This paper investigates the target detection performance of spectrum sharing MIMO radars that adapt their waveforms to avoid interference with cellular systems, proposing a null-space projection method and analyzing its effectiveness.

Contribution

It introduces a null-space projection algorithm for MIMO radars to share spectrum with cellular systems while maintaining detection performance, a novel approach in spectrum sharing.

Findings

Null-space projected waveform reduces interference to cellular BSs.

Detection performance of NSP waveform is comparable to orthogonal waveform.

Theoretical and simulation results validate the effectiveness of the proposed method.

Abstract

Future wireless communication systems are envisioned to share radio frequency (RF) spectrum, with other services such as radars, in order to meet the growing spectrum demands. In this paper, we consider co-channel spectrum sharing between cellular systems and radars. We address the problem of target detection by radars that are subject to shape its waveform in a way that it does not cause interference to cellular systems. We consider a multiple-input multiple-output (MIMO) radar and a MIMO cellular communication system with $\mc K$ base stations (BS). We propose a spectrum sharing algorithm which steers radar nulls, by projecting radar waveform onto the null space of interference channel, towards a `selected' BS, thus, protecting it from radar interference. This BS is selected, among $\mc K$ BSs, on the basis of guaranteeing minimum waveform degradation. We study target detection capabilities of this null-space projected (NSP) waveform and compare it with the orthogonal waveform. We derive the generalized likelihood ratio test (GLRT) for target detection and derive detector statistic for NSP and orthogonal waveform. The target detection performance for NSP and orthogonal waveform is studied theoretically and via Monte Carlo simulations.