论文标题
在相位噪声下使用OFDM进行单静力传感：从缓解到剥削
Monostatic Sensing with OFDM under Phase Noise: From Mitigation to Exploitation
论文作者
论文摘要
我们考虑在振荡器缺陷引起的相位噪声（PN）中，使用正交频划分（OFDM）关节雷达 - 通信（JRC）系统的单次雷达传感问题（JRC）。首先，我们在雷达接收器中提供了严格的PN统计表征，该表征在多个OFDM符号上提供自由运行的振荡器（FROS）和相锁环（PLL）。基于依赖延迟的PN协方差矩阵，我们得出了确定性延迟多普勒参数和随机PN的混合最大可能性（ML）/最大A-Posterii（MAP）估计器，从而导致挑战性的高维非线性优化问题。为了避免PN的非线性，我们开发了一个迭代的小角度近似（ISAA）算法，该算法通过PN的闭合形式更新逐步完善延迟多个二型PN估计，这是每次迭代处延迟多普勒的函数。此外，与现有的方法不同的方法被认为纯粹是必须缓解的损害的方法，我们建议通过利用其延迟依赖性统计数据（即范围相关效应）来利用PN来解决范围的歧义，并通过制定参数toeplitz-block-block-block-block-block-block toeplitz covaritz covaritz covaritix recontintsirintions Incellintirive rectruntim Incellix cormentirix Incellix Incellix Incellix Incellix Incruction Incruction Incortion Incortion Inctrifion Incorction。仿真结果表明，ISAA在各种操作条件下的FROS和PLL都可以快速收敛到混合Cramér-Rao Bound（CRB），以及其在最先进的基准测试中的显着性能提高，同时表明PN的有害效应可以使PN的有害效应变成传感的优势。
We consider the problem of monostatic radar sensing with orthogonal frequency-division multiplexing (OFDM) joint radar-communications (JRC) systems in the presence of phase noise (PN) caused by oscillator imperfections. We begin by providing a rigorous statistical characterization of PN in the radar receiver over multiple OFDM symbols for free-running oscillators (FROs) and phase-locked loops (PLLs). Based on the delay-dependent PN covariance matrix, we derive the hybrid maximum-likelihood (ML)/maximum a-posteriori (MAP) estimator of the deterministic delay-Doppler parameters and the random PN, resulting in a challenging high-dimensional nonlinear optimization problem. To circumvent the nonlinearity of PN, we then develop an iterated small angle approximation (ISAA) algorithm that progressively refines delay-Doppler-PN estimates via closed-form updates of PN as a function of delay-Doppler at each iteration. Moreover, unlike existing approaches where PN is considered to be purely an impairment that has to be mitigated, we propose to exploit PN for resolving range ambiguity by capitalizing on its delay-dependent statistics (i.e., the range correlation effect), through the formulation of a parametric Toeplitz-block Toeplitz covariance matrix reconstruction problem. Simulation results indicate quick convergence of ISAA to the hybrid Cramér-Rao bound (CRB), as well as its remarkable performance gains over state-of-the-art benchmarks, for both FROs and PLLs under various operating conditions, while showing that the detrimental effect of PN can be turned into an advantage for sensing.
