With the advancement of wireless communication systems, the demand for higher data rates is increasing exponentially. Non Orthogonal Multiple Access (NOMA) is expected to play an important role in 5G new radio networks. In contrast to conventional multiple access schemes, NOMA allows different users to efficiently share the same resources (i.e., time, frequency and code) at different power levels so that the user with lower channel gain is served with a higher power and vice versa. Multiple Input Multiple Output (MIMO) technology to support multiple users, employ tens or even hundreds of antennas at the base station which increases throughput and spectrum efficiency. The combination of NOMA and MIMO techniques can achieve significant performance gains and provide better wireless services to cope with the demands of massive connectivity. In this thesis, we analyze the performance of NOMA-MIMO system. We derive analytical expressions for the performance metrics like Outage Probability (OP) and Symbol Error Rate (SER) in power domain of NOMA-MIMO communication system. The numerical results are validated with the simulation results in MATLAB and the influencing factors for better performance of the system are analysed.