  In this letter, we aim to design a robust hybrid precoder and combiner
against beam misalignment in millimeter-wave (mmWave) communication systems. 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. An iterative algorithm is then proposed to
design the robust hybrid precoder and combiner to maximize the array gain in
the presence of beam misalignment. To further enhance the spectral efficiency,
a second-stage digital precoder and combiner are included to mitigate the
inter-stream interference. Numerical results show that the proposed robust
hybrid precoder and combiner design can effectively alleviate the performance
degradation incurred by beam misalignment.
