Joint Range and Doppler Estimation Using Spectrally Efficient FDM

This paper explores the use of data modulated by a spectrally efficient frequency division multiplexing (SEFDM) waveform for sensing. We first show that, if the presence of a cyclic prefix is assumed in the transmitted signal, the problem of multiple target sensing is tantamount to the detection and estimation of an unknown number of complex two-dimensional complex tones. Then, a novel iterative estimation method, based on a maximum likelihood approach, is developed to solve the last problem. Our simulation results evidence that SEFDM represents a valid technical option over static or slowly varying channels, and that the proposed method achieves a better accuracy-complexity trade-off than other estimation techniques available in the technical literature. In particular, our numerical results show that, in various scenarios, the proposed method achieves a 15% – 50% improvement in estimation accuracy with respect to other techniques with a limited computational complexity.