This paper addresses channel estimation for linear time-varying (LTV) wireless propagation links under the assumption of double sparsity i.e., sparsity in both the delay and the Doppler domains. Affine frequency division multiplexing (AFDM), a recently proposed waveform, is shown to be optimal (in a sense that we make explicit) for this problem. With both mathematical analysis and numerical results, the minimal pilot and guard overhead needed for achieving a target mean squared error (MSE) while performing channel estimation is shown to be the smallest when AFDM is employed instead of both conventional and recently proposed waveforms.
@article{arxiv.2306.07765,
title = {Affine Frequency Division Multiplexing For Communications on Sparse Time-Varying Channels},
author = {Wissal Benzine and Ali Bemani and Nassar Ksairi and Dirk Slock},
journal= {arXiv preprint arXiv:2306.07765},
year = {2023}
}