Input Distribution Design for Ranging-Oriented OFDM-ISAC Systems Under Frequency-Selective Fading
It addresses the practical need for efficient constellation design in 6G ISAC systems, but the approach is incremental, building on existing capacity-distortion theory.
The paper proposes a computationally efficient input distribution (constellation) design for OFDM-ISAC systems under frequency-selective fading, achieving a favorable trade-off between communication rate and sensing performance by allocating kurtosis across subcarriers.
The implementation of the \ac{isac} feature in \ac{6g} networks is most likely to be based on the framework of \ac{ofdm}. Input distribution design, or constellation design, is a crucial technique in \ac{ofdm}-\ac{isac} systems enabling a favorable balance between communication rate and sensing performance. In this treatise, we propose a computationally efficient input distribution design approach for \ac{ofdm}-\ac{isac} under frequency-selective channels, following the theoretical framework of capacity distortion. We highlight that under practical sensing constraints, the optimal strategy is to treat the kurtosis of constellations as a resource, and allocate it appropriately over subcarriers.