This thesis investigates the performance of a multi-user multiple-input single- output (MISO) system considering maximum ratio transmission (MRT) downlink precoding. The transmitted signal from the base station (BS) to each user is as- sumed to experience the double scattering channel. We adopt the minimum-mean- square-error (MMSE) channel estimator for the proposed model. Within this setting, we are interested in deriving tight approximations of the ergodic rate assuming the number of BS antennas, users, and scatterers grow large with the same pace. Under the special multi-keyhole channels, these deterministic equivalents are expressed in more simplified closed-form expressions. The simplified expressions reveal that unlike the standard Rayleigh channel in which the SINR grows as as O(N/k), the SINR associated with a multi-keyhole channel scales as O(S/N). This particularly shows that the K reaped gains of the large-scale MIMO over double scattering channels do not linearly increase with the number of antennas and are limited by the number of scatterers. We further show that the derived asymptotic results match the simulation results closely under moderate system dimensions and provide some useful insights into the interplay between N, K and S.