Directional-DRX for 5G wireless communications

Directional-discontinuous reception (D-DRX) is proposed for millimetre-wave enabled fifth-generation communications. In addition to conventional active, short-sleep and long-sleep states, the proposed mechanism considers a separate beam searching state, to address alignment of directional beams between user equipment (UE) and evolved node B after a sleep cycle. Semi-Markov process is explored to capture various states of UE and probabilistically estimate its power saving and delay. A numerical analysis is conducted to validate the performance of D-DRX proposal. About 10% improvement is achieved in power saving with a marginal decrease in delay compared with maximum possible beam search time.