Performance analysis of the beamformer for imperfect antenna array in QPSK

The performance of quadrature phase shift keying (QPSK) modulation with a beamformer is analyzed in the presence of array imperfections. A close-form expression is derived for the probability of a symbol error (PSE). Simulation results demonstrate that the presented beamformer based on the least squares method of subarrays (LSMS) outperforms the linearly constrained minimum variance (LCMV) method and is close to the optimal beamformer requiring known complex gain perturbation in terms of array patterns and symbol error rates (SERs).