A Novel Approach to mmWave Transmission in Cooperative Massive MIMO Systems Based on NOMA Technology

With the increasing traffic in wireless networks, the need for new techniques to improve connectivity, bandwidth, and spectrum access is essential. The combination of massive multiple-input multiple-output (MIMO) and non-orthogonal multiple access (NOMA) technologies has been proposed as a promising solution to meet the increasing data rate demand, using the millimeter wave (mmWave) band and improving system performance. In this research, a mmWave transmission method based on NOMA technology and massive MIMO with a cooperative structure and distributed antenna is presented. The problem of optimizing the total rate in the proposed system is considered under the constraints of the same power and total power of the base station. In order to reduce the complexity of the proposed method, the maximum ratio combining method based on the repetitive strategy (MRC-RS) was used. The main problem in achieving multi-user gain in massive MIMO systems is the dependence on channel state information (CSI). To solve this problem, insertion division multiple access (IDMA) and data-aided channel estimation (DACE) were proposed. Simulation results show that the proposed method performs better than other previous methods in terms of energy efficiency and spectrum efficiency. Also, the proposed method has achieved significant performance against the pilot contamination problem and reduced complexity in the receiver.