A Two-Stage Radar Sensing Approach based on MIMO-OFDM Technology

TL;DR

This paper proposes a novel two-stage radar sensing method using MIMO-OFDM technology, leveraging existing communication systems to estimate target channels and locations efficiently, even for closely spaced targets.

Contribution

It introduces a two-stage approach combining OFDM channel estimation and MIMO techniques for environment sensing within communication systems, enabling accurate target detection and localization.

Findings

Effective channel estimation using compressed sensing in Stage I.

Enhanced target localization with MIMO spatial sampling in Stage II.

Numerical results demonstrate the approach's practicality and accuracy.

Abstract

Recently, integrating the communication and sensing functions into a common network has attracted a great amount of attention. This paper considers the advanced signal processing techniques for enabling the radar to sense the environment via the communication signals. Since the technologies of orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) are widely used in the legacy cellular systems, this paper proposes a two-stage signal processing approach for radar sensing in an MIMO-OFDM system, where the scattered channels caused by various targets are estimated in the first stage, and the location information of the targets is then extracted from their scattered channels in the second stage. Specifically, based on the observations that radar sensing is similar to multi-path communication in the sense that different targets scatter the signal sent by the radar transmitter to the radar receiver with various delay, and that the number of scatters is limited, we show that the OFDM-based channel training approach together with the compressed sensing technique can be utilized to estimate the scattered channels efficiently in Stage I. Moreover, to tackle the challenge arising from range resolution for sensing the location of closely spaced targets, we show that the MIMO radar technique can be leveraged in Stage II such that the radar has sufficient spatial samples to even detect the targets in close proximity based on their scattered channels. Last, numerical examples are provided to show the effectiveness of our proposed sensing approach which merely relies on the existing MIMO-OFDM communication techniques.