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

Here we examine the performance of the generalized eigenspace-based beamfor mer (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-interferen ce-plus-noise ratios (SINRs) of the GEIB and the linearly constrained minim um variance beamformer (LCMVB) are evaluated. Analysis results show that th e 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 angl e of the interferer varies, the output SINR of the GEIB may oscillate, espe cially in the case that only the unit gain constraint is applied. When the input interference-to-noise ratio (INR) approaches infinity, the level of o scillation reduces to zero and the GEIB achieves almost the optimal output SNR. We compare the performances of the GEIB acid the LCMVB, and find that the GEIB can achieve nearly the optimal output signal-to-noise ratios (SNR) when the LCMVB has a loss of 10 log M dB, where M is the sensor number, du e to pointing errors. (C) 1999 Elsevier Science B.V. All rights reserved.