Space-Time Coding MIMO-OFDM SAR for High-Resolution Imaging
Space-Time Coding MIMO-OFDM SAR for High-Resolution Imaging
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DOI：
10.1109/tgrs.2011.2116030
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发表时间：
2011-08-01
影响因子：
8.2
通讯作者：
Wang, Wen-Qin
中科院分区：
文献类型：
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作者：
Wang, Wen-Qin
多输入多输出（MIMO）雷达近年来重新受到人们的关注，但关于MIMO合成孔径雷达（SAR）遥感的研究报道很少。提出了一种空时编码MIMO正交频分复用（OFDM）SAR高分辨率成像方案。该系统在仰角方向采用MIMO结构，在方位角方向采用阿拉米空时编码方案，同时沿着使用OFDM波形分集和相位中心偏移天线（DPCA）技术。针对空时编码MIMO-OFDM合成孔径雷达系统要求传输波形正交的特点，研究了一种OFDM线性调频波形。详细介绍了匹配滤波和仰角方向多波束形成。建立了相应的数学关系和高分辨成像信号模型。该方法通过MIMO结构获得了有效的空间分集增益，提高了距离分辨率，并通过DPCA技术降低了宽测绘带遥感对脉冲重复频率的要求。数值模拟结果验证了该方法的可行性。
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.