Outage Investigation of Beamforming Over Random-Phase Finite-Scatterer MISO Channels

In this letter, we revisit single-user multiple-input single-output beamforming with imperfect channel state information (CSI) at the transmitter. We present a CSI estimation model that is suitable for finite-scatterer directional channel models with uncertainty in the relative phase shifts of the scattering components. We show that in this case the distribution of the effective beamformed channel does not follow one of the well-known channel fading distributions and leads to complicated outage calculations. We show that the presented model generalizes popular existing models and we relate our investigations for the special cases of one and two specular components to existing results. We furthermore consider signal outage optimal beamforming for the case of two specular components.