Amplitude and phase optimization for adaptive antenna arrays via spatially smoothed ESPRIT
Fung-I Tseng, Jayanti Venkataraman · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
The paper presents two adaptive techniques, namely, the phase-only adjustment and the amplitude-phase optimization. In each case it creates multiple nulls to suppress multiple jammers. The adaptive technique is based on forward and backward smoothed ESPRIT (estimation of signal parameters via rotational invariance technique), which is capable of handling both coherent and non-coherent narrow-band multiple signals. For the amplitude-phase optimization both current amplitudes and phases are simultaneously adjusted to maximize the SIR (signal-to-interference ratio), which does not require iteration. The phase-only adaptive technique assumed fixed amplitudes while phases are adjusted, which required iterative algorithm. In both cases it is demonstrated to be effective and efficient. Computer simulations for a linear array of 32 elements and eight incoming signals have shown that the optimization technique can create wide as well as deep nulls, which correspond well to jammer widths and strengths. In each case the SIR improves substantially and the phase-amplitude optimization has much better SIR improvement than that of the phase-only adjustment.