Optimized Non-Uniform Pilot Pattern for OFDM Sensing

TL;DR

This paper introduces a novel non-uniform pilot pattern design for OFDM systems that reduces sensing interference and improves radar resolution without harming communication performance.

Contribution

It proposes a two-stage framework and a hybrid greedy-stochastic algorithm to optimize pilot patterns, effectively suppressing grating lobes in OFDM sensing.

Findings

Enhanced range RMSE in sensing applications.

Maintained communication BER performance.

Suppressed deterministic grating lobes below DPI noise floor.

Abstract

Standard periodic pilot patterns in orthogonal frequency division multiplexing (OFDM) systems induce severe delay-domain grating lobes, compromising radar sensing. This paper proposes a two-stage framework to design non-periodic pilot patterns that minimize the peak sidelobe level (PSL) while strictly enforcing communication anchor constraints. We black solve this combinatorial problem using a low-complexity hybrid greedy-stochastic cyclic coordinate descent (SCCD) algorithm. This approach shatters cyclic periodicities to suppress deterministic grating lobes beneath the impassable data-to-pilot interference (DPI) noise floor. System-level evaluations demonstrate the performance of the proposed design in resolving the sensing-communication trade-off, showing improved range root mean square error (RMSE) without degrading the primary communication bit error rate (BER).