基于Alamouti编码的MIMO-SAR高信噪比高分辨宽测绘带成像

High Signal to Noise Ratio and High Resolution Wide Swath Imaging of MIMO-SAR Based on Almouti Space-Time Encoding

提出了一种基于Alamouti空时编码的方位-慢时间波形编码方案.系统沿方位向分两个子孔径按Alamouti编码矩阵对正交波形作脉间编码发射,接收端全阵列分子孔径接收,通过对回波信号作方位多普勒解模糊,再解码处理Alamouti编码组内相邻两个脉冲重复间隔(PRI)的回波信号,实现了正交子波形的彻底分离,改善了回波信号的信噪比,可实现高信噪比下高分辨宽测绘带成像.系统结构简单,孔径资源利用率高,且具有同时多模式工作潜力.仿真分析验证了系统信号处理方法的正确性.

A new mode named azimuth-slow time waveform coding based on Alamouti space-time coding is presented .In azimuth ,the total antenna array is divided into two sub-apertures for transmitting orthogonal waveforms that encoded by Alamouti coding matrix .In receiver ,the total antenna array is divided into multiple sub-apertures forming multiple receive phase centers , which can be used for azimuth doppler ambiguity deduction ,then the decoding of neighbor pulses can separate the orthogonal sub-waveforms thoroughly .This new method can enhance the echoes’ SNR obviously and also realize high resolution wide swath imag-ing .The proposed system is of terseness ,the aperture is fully explored ,the SNR of echoes is improved ,and the potential of multiple working modes simultaneously ,etc .The simulation Results verify the system signal processing method .