With the increasing demand for network services and a growing number of users, 5G communication systems have stringent requirements to fulfill. Due to this reason, 5G systems should employ capacity­-oriented base station antenna arrays and beamforming techniques. In this regard, multibeam antenna systems have gained immense attention. Currently, there is a missing link between antenna engineering and communication system design. Traditionally, antenna array design focused on optimizing free space propagation parameters like gain, directivity, sidelobe levels, etc. However, in order to achieve maximum network capacity, antenna array and beamforming techniques should consider a realistic system model and propagation environment. In this thesis work, we bridge the gap between antenna engineering and communication system design by proposing a multi­user communication system model that considers channel modeling, modulation, and RF aspects. Further, we use this model to assess the user performance in terms of Error Vector Magnitude (EVM) and Bit Error Rate (BER) for various base station antenna configurations and user positions. The results obtained showed that using an irregular antenna array at the base station with 64 elements shows an improvement in the performance of the users. With the presented simulation results, the system engineers can design efficient antenna arrays at the base station to achieve good performance on the millimeter wave frequency bands.