Input Distribution Design for Ranging-Oriented OFDM-ISAC Systems Under Frequency-Selective Fading

2026-04-29

AI Summary

This work addresses the fundamental trade-off between communication rate and sensing performance in OFDM-based integrated sensing and communication (ISAC) systems operating over frequency-selective fading channels. For the first time, constellation kurtosis is treated as a schedulable resource, and within a rate-distortion theoretic framework, the authors propose a computationally efficient input distribution design method. By optimally allocating kurtosis across subcarriers, the approach achieves a favorable ISAC performance trade-off tailored for ranging applications. The proposed method jointly integrates constellation design, kurtosis resource allocation, and OFDM-ISAC system modeling, significantly enhancing the synergy between communication throughput and sensing accuracy under practical sensing constraints, thereby improving overall system effectiveness.

Abstract

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.

Problem

• OFDM-ISAC
• input distribution design
• frequency-selective fading
• ranging
• constellation design

Innovation

• OFDM-ISAC
• input distribution design
• kurtosis allocation
• frequency-selective fading
• capacity-distortion theory