FDA-MIMO-based Integrated Sensing and Communication System with Frequency Offset Permutation Index Modulation

TL;DR

This paper introduces an FDA-MIMO-based integrated sensing and communication system utilizing frequency offset permutation index modulation, with novel detection methods and theoretical bounds, achieving improved BER and range resolution.

Contribution

It proposes a new FOPIM scheme for enhanced communication and develops efficient detection algorithms and bounds for FDA-MIMO ISAC systems.

Findings

Lower BER compared to traditional methods

Superior range resolution demonstrated in simulations

Theoretical bounds validated by simulation results

Abstract

Considering that frequency diverse array multiple-input multiple-output (FDA-MIMO) possesses extra range information to enhance sensing performance, this paper explores the FDA-MIMO-based integrated sensing and communication (ISAC) system. To reinforce the system communication capability, we propose the frequency offset permutation index modulation (FOPIM) scheme, which conveys extra information bits by selecting and permutating frequency offsets from a frequency offsets pool. For the system communication sub-functionality, considering the fact that the traditional maximum likelihood detection method suffers from high complexity and bit error rate (BER), the maximum likelihood-based two-stage detection (MLTSD) approach is presented to overcome this issue. For the system sensing sub-function, we employ the two-step maximum likelihood estimator (TSMLE) to stepwise estimate the angle and range of the interested target. Furthermore, we derive the closed-form expressions for the tight upper bound on the communication BER, along with the sensing Cram\'er-Rao bound (CRB). The simulation results validate the theoretical analysis, demonstrating that the proposed system exhibits lower BER and superior range resolution than independent MIMO communication and MIMO sensing modules.