— Synthetic Aperture Radar (SAR) has been widely used for a well-proven remote sensing technique for more than 30 years. However, single-antenna SAR systems cannot achieve wide-swath and high-resolution imaging at the same time. Multi-Input Multi-Output (MIMO) radar can be used to form a synthetic aperture for high resolution imaging. To successfully utilize the MIMO-SAR system for practical imaging application, the orthogonal waveform design plays a critical role in image formation. In this paper, we modify the transmitted signal of the discrete frequency coding waveform with linear frequency modulation (DFCW-LFM) for MIMO-SAR from fixed chirp rate to variable chirp rate. Changing between the up –and down-chirp waveform can integrated between DFCW and Orthogonal Frequency Division Multiplexing (OFDM) to improve integrated side-lobe level ratio (ISLR) and peak side-lobe level ratio (PSLR) for MIMO-SAR. Modified genetic algorithm (GA) is proposed to numerically optimize the DFCW based OFDM. Some of the designed results are presented.
— MIMO-SAR, SAR applications, orthogonal waveform design, discrete frequency-coding waveform, OFDM, genetic algorithm.
Wael Mehany, Licheng Jiao, and Xiangrong Zhang are with School of Electronic Engineering, Xidian University, Xi'an, China (e-mail: waelelfarra@ yahoo.com).
Cite: Wael Mehany, Licheng Jiao, and Xiangrong Zhang, " Design Discrete Frequency Coding Waveform Based OFDM for MIMO-SAR," International Journal of Information and Electronics Engineering vol. 5, no. 2, pp. 126-130, 2015.