Performance of generalized eigenspace-based beamformers in the presence of pointing errors

Abstract

Here we examine the performance of the generalized eigenspace-based beamformer (GEIB) with derivative constraints in the presence of pointing errors. Under the assumption that the signal scenario consists of a desired signal, an interferer and additive receiver noise, the output signal-to-interference-plus-noise ratios (SINRs) of the GEIB and the linearly constrained minimum variance beamformer (LCMVB) are evaluated. Analysis results show that the output SINR of the GEIB considerably depends on an interferer located in the sidelobe region, while that of the LCMVB does not. As the arriving angle of the interferer varies, the output SINR of the GEIB may oscillate, especially in the case that only the unit gain constraint is applied. When the input interference-to-noise ratio (INR) approaches infinite, the level of oscillation reduces to zero and the GEIB achieves almost the optimal output SNR. We compare the performances of the GEIB and the LCMVB, and find that the GEIB can achieve nearly the optimal output signal-to-noise ratios (SNRs) when the LCMVB has a loss of 10 log M dB, where M is the sensor number, due to pointing errors.