MIMO-SAR orthogonal waveform set design based on random subcarriers OFDM signal

摘要

The orthogonal waveform set with excellent characteristics is one of the key technologies to realize the advantages of the MIMO-SAR radar system. Among them, the orthogonality and Doppler tolerance are the most urgent requirements. The waveform sets with approximate rational orthogonality can be generated using interleaved subcarriers OFDM (I-OFDM) technique while maintaining the same range resolution as the OFDM signal, which has been paid more attention in MIMO radar waveform design. However, the narrow orthogonal time-delay range limits the design and application of I-OFDM orthogonal waveform sets. In this paper, random subcarriers OFDM (R-OFDM) design method is proposed. First, the cost function is constructed based on the PSLR and ISLR value of the autocorrelation and cross-correlation ambiguity function. Then, the subcarriers frequency distribution structure and the weighted scheme are obtained by the optimization algorithm. At last, the performance of the proposed waveform sets is verified by computer simulation.