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arXiv · 2605.21729

Rate-Splitting--Inspired Bistatic OFDM-ISAC

Bruno F. Costa·Anup Mishra·Israel Leyva-Mayorga·Taufik Abrão·Petar Popovski
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Abstract

Achieving effective uplink bistatic ISAC over an OFDM waveform gives rise to challenging interference structures. These are mostly due to unequal direct- and echo-path contributions and Doppler-induced ICI, rendering orthogonal resource separation and fixed SIC strategies inadequate. To address this problem, we propose a RS-inspired framework where the transmitter splits each communication message into a robust and a supplementary stream, which are jointly superposed over a sensing signal. Furthermore, we present the design of a staged sensing-communication receiver. Based on this framework, we derive tractable per-subcarrier SINR expressions and establish the relation between sensing accuracy and communication reliability based on the Fisher information. Building on these, we formulate a joint power-allocation problem for SE maximization under sensing-performance and power constraints. The resulting non-convex formulation is solved using convex surrogates and fractional programming. Numerical results demonstrate that, compared to NOMA-inspired baselines, the proposed framework provides more effective IFI management and improved robustness to Doppler-induced ICI.

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Bruno F. Costa, Anup Mishra, Israel Leyva-Mayorga, Taufik Abrão, Petar Popovski. 2026-05-20. Rate-Splitting--Inspired Bistatic OFDM-ISAC. https://arxiv.org/abs/2605.21729

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