Beam Misalignment Aware Hybrid Transceiver Design in mmWave MIMO Systems

In this letter, we design a beam misalignment aware hybrid analog-digital transceiver to minimize the performance loss owing to imperfect beam alignment in millimeter-wave (mmWave) communication systems. Specifically, we consider the inclusion of the 'error statistics' into the precoder and combiner design, where the array response that incorporates the distribution of the misalignment error is first derived. The derived array response spreads the directivity of the beam pattern around the desired direction, thereby minimizing the loss in the array gain under beam misalignment. Accordingly, based on the derived array response, we design the hybrid precoder and combiner approach by approximating their fully-digital design using the gradient projection method. Numerical results show that the proposed hybrid precoder and combiner design can effectively alleviate the performance degradation incurred by beam misalignment.