Frequency-difference beamforming (FDB) provides a robust estimation of wave propagation direction by shifting signal processing to a lower frequency which, however, produces a decline in the spatial resolution. In this letter, the beam pattern of FDB for a distant point source is proved to be shift invariant and therefore can be regarded as the point spread function corresponding to FDB's beam output. Then, deconvolved frequency-difference beamforming (Dv-FDB) is proposed to improve array performance. Dv-FDB yields a narrower beam and lower sidelobe levels while maintaining robustness. The superior performance of Dv-FDB is verified by simulations and experimental data.

中文翻译：

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线性阵列的解卷积频差波束形成

频差波束形成（FDB）通过将信号处理移至较低的频率来提供对波传播方向的可靠估计，但会导致空间分辨率下降。在这封信中，证明了远距离点源的FDB的光束方向图是位移不变的，因此可以视为与FDB的光束输出相对应的点扩展函数。然后，提出了反卷积频差波束形成（Dv-FDB）以提高阵列性能。Dv-FDB产生较窄的波束和较低的旁瓣电平，同时保持鲁棒性。仿真和实验数据验证了Dv-FDB的优越性能。