Robust adaptive beamforming via virtual array transformation

In this paper we first introduce the virtual transformation with interpolation techniques which maps the data from a real antenna array onto a VA structure, and then the performance of VA is investigated through simulations using arrays of the dissimilar geometries. Simulations show that the performance is not in proportion with the sensor number of the VA and it is optimal when the aperture of the VT is approximately equal to that of the real array. The selected interpolation sector area should not be too large; otherwise the transformation error will increase rapidly. The shortcoming of the method is that it requires the prior knowledge of the direction of interferers and the VA may lose some characteristic of the original array, for example, the omnidirectional estimation capability and high resolution of the UCA