杂波环境中基于四阶同信道干扰感知的OFDM-ISAC传感

中文摘要 AI 辅助

本文针对单站正交频分复用集成感知与通信（OFDM-ISAC）系统，在被动杂波与非合作同信道OFDM发射机同时存在的场景下，开发了一种以感知为中心的接收机。我们证明，移除已知的ISAC符号可将目标回波和杂波回波映射为确定性的延迟-多普勒分量，而非合作波形则保持为随机、非高斯、一般满秩的残差。基于这一区分，我们将针对零多普勒杂波的动目标指示与用于干扰识别的中心化对角四阶统计量相结合。为了从相位对齐的适当快照中获得无偏的四阶估计，我们推导了加性和乘性有限样本偏差校正，并将校正后的统计量与二阶矩配对，以将干扰与高斯噪声分离。四阶统计量提供识别和存在性检验，而二阶统计量提供用于加权的对角干扰功率代理。我们进一步引入了对角加载权重，以强制执行距离-多普勒孔径效率下限。仿真表明，随着相干支持的增长，干扰估计趋近其理论轮廓，并且对确定性回波不敏感；存在性检验能够在加权起作用的水平以下很好地分辨干扰；加载处理在控制点扩散函数退化的同时提高了目标检测性能。

英文摘要

In this paper, we develop a sensing-centric receiver for monostatic orthogonal frequency-division multiplexing integrated sensing and communication (OFDM-ISAC) in the simultaneous presence of passive clutter and a non-cooperative co-channel OFDM transmitter. We show that removing the known ISAC symbols maps target and clutter echoes to deterministic delay-Doppler components, while the non-cooperative waveform remains a random, non-Gaussian, generically full-rank residual. Guided by this distinction, we combine moving-target indication for zero-Doppler clutter with a centered diagonal fourth-order statistic for interference identification. To obtain an unbiased fourth-order estimate from phase-aligned proper snapshots, we derive additive and multiplicative finite-sample bias corrections and pair the corrected statistic with a second-order moment to separate interference from Gaussian noise. Fourth order provides identification and presence testing, whereas second order provides the diagonal disturbance-power proxy used for weighting. We further introduce diagonally loaded weights that enforce a range-Doppler aperture-efficiency floor. Simulations show that the interference estimate approaches its theoretical profile as coherent support grows and remains insensitive to deterministic echoes, that the presence test resolves interference well below the level at which weighting matters, and that loaded processing improves target detection while controlling point-spread-function degradation.

发表机构

• Polytechnique Montréal（蒙特利尔理工学院）

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