多输入多输出雷达中混合分集波形方案效应的表征
Characterizing the Effects of Mixed Division Waveform Schemes in MIMO Radar
- University of Birmingham（伯明翰大学）
- University of Liverpool（利物浦大学）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文研究MIMO雷达中混合分集波形方案对正交性和波束形成性能的影响，发现混合策略显著降低波形正交性，导致测向误差和旁瓣升高，且大量组合波形质量不佳。
中文摘要 AI 辅助
多输入多输出（MIMO）雷达中的离开方向估计基于发射一组正交（或至少可分离）的波形，每个发射单元对应一个波形。假设正交性得以保持，这些波形在接收端波束形成前可被分离到不同通道中。然而，在实际中，MIMO波形并非完全正交，在处理链的不同阶段，这可能在波束形成所用的导向矢量中表现为相位误差。此外，由于信道或感知场景的资源限制，常常采用多种正交技术的混合，即混合分集策略，这会引入进一步的相位误差。自然，这些误差会干扰波束形成过程，破坏波束，引入测向误差，或增加旁瓣电平，从而降低信噪比。在本文中，我们展示了混合分集策略如何显著降低原本正交波形的正交性，导致波束形成性能下降。具体而言，我们表明，具有良好旁瓣电平的波形仍可能引起大的离开方向误差，反之亦然。此外，通过对时间、多普勒和码分技术组合的潜在混合分集策略进行多次穷举搜索，我们表明大量可能的波形表现出较差的波束形成质量。
英文摘要
Direction of departure estimation in Multiple-Input-Multiple-Output (MIMO) radar is based on transmitting a set of orthogonal (or at least separable) waveforms, one per transmit element. Assuming orthogonality is preserved, these waveforms can then be separated into different channels at the receiver before beamforming. In practice, however, MIMO waveforms are not perfectly orthogonal, and at different points in the processing chain, this can manifest as phase errors in the steering manifolds used in beamforming. Furthermore, due to resource constraints, either by the channel or the sensing scenario, a mixture of orthogonality techniques, mixed division strategies, are often employed, resulting in further phase errors. Naturally, such errors will interfere in the beamforming process, spoiling the beam, introducing direction finding errors, or increasing sidelobe levels, and consequently reducing SNR. In this paper, we demonstrate how mixing division strategies significantly degrades orthogonality of otherwise orthogonal waveforms resulting in degraded beamforming performance. Specifically, we show that waveforms which exhibit favourable sidelobe levels may still induce large direction of departure errors and vice versa. Additionally, through multiple exhaustive searches of potential mixed division strategies with combinations of time-, Doppler- and code-based division techniques we show that large numbers of the possible waveforms exhibit poor beamforming qualities.
