Beamforming with time-delay compensation for 60 GHz MIMO frequency-selective channels

Due to the very large transmission bandwidth of millimeter wave (mmWave) communications, the fading channel is expected to be frequency selective. Recent work in this field has mainly focused on cyclic-prefixed OFDM as a method to combat the frequency selectivity. But in this paper, we shift the focus on the novel method of time delay compensation to obtain a flat channel over wide bandwidth since it proves to be a more effective method reducing the computational complexity and achieving the high power efficiency at the receiver side. We employ time-shifted beams to compensate the delay spread and achieve high directionality. We also study the influence of physical parameters such as delay spread and system parameters such as the number of antennas on ergodic capacity and outage capacity. Finally, the proposed method is validated by providing numerical examples by means of simulation.