Delay-Doppler Channel Estimation using Arbitrarily Modulated Data Transmissions
This addresses spectral efficiency issues in 6G communication systems, though it appears incremental as it builds on existing delay-Doppler frameworks.
The paper tackled the problem of spectral efficiency loss in delay-Doppler communication and sensing systems due to pilot transmissions, by proposing an approach that uses arbitrarily modulated data transmissions for channel estimation without pilots in every coherence interval, resulting in a ~1.8x improvement in spectral efficiency over conventional methods across various 6G modulation schemes.
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 $\sim 1.8 \times$ improvement in spectral efficiency with our proposed data-based approach over conventional pilot-based approaches across various 6G modulation schemes.