IRCI-Free CP-OFDM SAR Signal Processing

Recent literature shows that with sufficient cyclic prefix, orthogonal frequency-division multiplexing signals can convert a synthetic aperture radar (SAR) image with interrange cell interference (IRCI) to an IRCI-free SAR image. In this letter, the imaging algorithm is carefully investigated and it is shown that the range reconstruction accuracy can be further improved. By reformulating the system model in a linear model form, the minimum variance unbiased estimator of the range profile is derived, which can attain the Cramer-Rao lower bound, making our algorithm more effective than current algorithms under noisy conditions. Simulation results validate the advantages of the proposed algorithm, especially under low signal-to-noise ratio conditions.