Conventional delay-Doppler (DD) communication and sensing systems require transmitting pilot frames at every channel coherence time interval in order to keep track of channel variations at the cost of spectral efficiency. In this paper, we propose an approach to utilize data transmissions modulated using arbitrary waveforms for DD channel estimation without requiring pilot transmissions in every coherence time interval. Numerical evaluation over practical doubly-selective channel models demonstrate ∼1.8× improvement in spectral efficiency with our proposed data-based approach over conventional pilot-based approaches across various 6G modulation schemes.
@article{arxiv.2604.07308,
title = {Delay-Doppler Channel Estimation using Arbitrarily Modulated Data Transmissions},
author = {Nishant Mehrotra and Sandesh Rao Mattu and Robert Calderbank},
journal= {arXiv preprint arXiv:2604.07308},
year = {2026}
}