LAUSR

In this letter, beam selection and power allocation are investigated for maritime offshore communications. Considering the slow-changing network topology and the line-of-sight (LOS) dominant propagation of land-sea links, we define a beam configuration period (BCP) as a time span to contain numerous coherence intervals (CIs), and provide a two-timescale design by enforcing the long-term beam selection strategy and the short-term power allocation scheme only once in every BCP and in every CI, respectively. Since the beamforming configurations are updated much less frequently, the training overhead could be considerably reduced. Numerical results indicate that the proposed two-timescale design avoids heavy training overhead, and thus effectively enhances the performance of offshore communications.