In this paper, we analyze the periodic transmission masks for MASked Modulation (MASM) in half-duplex integrated sensing and communication (ISAC), and derive their closed-form expected range-Doppler response E{r(k,l,ν)}. We show that range sidelobes (k=l) are Doppler-invariant, extending the range-sidelobe optimality to the 2-D setting. For the range mainlobe (k=l), periodic masking yields sparse Doppler sidelobes: Cyclic difference sets (CDSs) (in particular Singer CDSs) are minimax-optimal in a moderately dynamic regime, while in a highly dynamic regime the Doppler-sidelobe energy is a concave function of the mask autocorrelation, revealing an inevitable tradeoff with mainlobe fluctuation.
@article{arxiv.2601.10259,
title = {Transmission Mask Analysis for Range-Doppler Sensing in Half-Duplex ISAC},
author = {Dikai Liu and Yifeng Xiong and Marco Lops and Fan Liu and Jianhua Zhang},
journal= {arXiv preprint arXiv:2601.10259},
year = {2026}
}