OFDM Synthetic Aperture Radar Imaging with Sufficient Cyclic Prefix

TL;DR

This paper introduces a novel OFDM SAR imaging method using sufficient cyclic prefix to eliminate inter-range-cell interference, achieving high range resolution and differentiating from existing OFDM radar techniques.

Contribution

The paper proposes a new OFDM SAR imaging algorithm with cyclic prefix insertion that converts IRCI channels into interference-free subchannels, enhancing resolution.

Findings

High range resolution demonstrated through simulations

Cyclic prefix effectively removes inter-range-cell interference

Differentiates from existing OFDM radar methods

Abstract

The existing linear frequency modulated (LFM) (or step frequency) and random noise synthetic aperture radar (SAR) systems may correspond to the frequency hopping (FH) and direct sequence (DS) spread spectrum systems in the past second and third generation wireless communications. Similar to the current and future wireless communications generations, in this paper, we propose OFDM SAR imaging, where a sufficient cyclic prefix (CP) is added to each OFDM pulse. The sufficient CP insertion converts an inter-symbol interference (ISI) channel from multipaths into multiple ISI-free subchannels as the key in a wireless communications system, and analogously, it provides an inter-range-cell interference (IRCI) free (high range resolution) SAR image in a SAR system. The sufficient CP insertion along with our newly proposed SAR imaging algorithm particularly for the OFDM signals also differentiates this paper from all the existing studies in the literature on OFDM radar signal processing. Simulation results are presented to illustrate the high range resolution performance of our proposed CP based OFDM SAR imaging algorithm.