Space-Time Coding MIMO-OFDM SAR for High-Resolution Imaging

• Published in: IEEE transactions on geoscience and remote sensing Vol. 49; no. 8; pp. 3094 - 3104
• Main Author: WANG, Wen-Qin
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-08-2011; Institute of Electrical and Electronics Engineers
• Subjects: Applied geophysics; Azimuth; Earth sciences; Earth, ocean, space; Encoding; Exact sciences and technology; Frequency modulation; High resolution and wide swath; Internal geophysics; MIMO; MIMO radar; MIMO SAR; multiple-input and multiple-output (MIMO)-orthogonal frequency division multiplexing (OFDM) synthetic aperture radar (SAR); OFDM; space-time coding; Synthetic aperture radar; Transmitting antennas; waveform diversity; antenna; models; simulation; space-time coding; waveform diversity; remote sensing; High resolution and wide swath; MIMO SAR; frequency; MIMO radar; multiple-input and multiple-output (MIMO)-orthogonal frequency division multiplexing (OFDM) synthetic aperture radar (SAR); filtering; waveforms; radar methods; Synthetic aperture radar; direction; high resolution
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2011.2116030

Multiple-input and multiple-output (MIMO) radar has received renewed attention in recent years, but little work on MIMO synthetic aperture radar (SAR) remote sensing has been reported. This paper presents a scheme of space-time coding MIMO orthogonal frequency division multiplexing (OFDM) SAR for high-resolution imaging. This system employs MIMO configuration in the elevation direction and the Alamouti space-time coding scheme in the azimuth direction, along with the use of OFDM waveform diversity and displaced phase center antenna (DPCA) techniques. As an orthogonal transmission waveform is required for this novel space-time coding MIMO-OFDM SAR system, one kind of OFDM linearly frequency modulated waveforms is investigated. The matched filtering and multibeam forming in the elevation direction are detailed. Additionally, the corresponding mathematical relations and signal models for high-resolution imaging are formed. In this way, efficient spatial diversity gain and improved range resolution are obtained by the MIMO configuration, and the requirement of pulse repeated frequency for wide-swath remote sensing is reduced by the DPCA technique. The feasibility is validated by numerical simulation results.