A Joint Design of MIMO-OFDM Dual-Function Radar Communication System Using Generalized Spatial Modulation

TL;DR

This paper introduces a MIMO-OFDM dual-function radar communication system that combines high-resolution target detection with high data rates by using a novel antenna activation and subcarrier allocation scheme.

Contribution

It proposes a joint design leveraging generalized spatial modulation and shared/private subcarriers for improved radar and communication performance.

Findings

High target resolution achieved through virtual array synthesis.

High communication rate enabled by shared subcarriers.

Robustness to frequency selective fading demonstrated.

Abstract

A novel dual-function radar communication (DFRC) system is proposed, that achieves high target resolution and high communication rate. It consists of a multiple-input multiple-output (MIMO) radar, where only a small number of antennas are active in each channel use. The probing waveforms are orthogonal frequency division multiplexing (OFDM) type. The OFDM carriers are divided into two groups, one that is used by the active antennas in a shared fashion, and another one, where each subcarrier is assigned to an active antenna in an exclusive fashion (private subcarriers). Target estimation is carried out based on the received and transmitted symbols. The system communicates information via the transmitted OFDM data symbols and the pattern of active antennas in a generalized spatial modulation (GSM) fashion. A multi-antenna communication receiver can identify the indices of active antennas via sparse signal recovery methods. The use of shared subcarriers enables high communication rate. The private subcarriers are used to synthesize a virtual array for high angular resolution, and also for improved estimation on the active antenna indices. The OFDM waveforms allow the communication receiver to easily mitigate the effect of frequency selective fading, while the use of a sparse array at the transmitter reduces the hardware cost of the system. The radar performance of the proposed DFRC system is evaluated via simulations, and bit error rate (BER) results for the communication system are provided.