In a cellular system, the base station is responsible only for cell coverage within a certain range and transmits data. However, transmitting data to users outside cell coverage is difficult. In addition, even if the cell user is within that range, there may be cases in which data are not properly transmitted owing to poor communication conditions. Therefore, the user QoS must be satisfied by relaying the data transmitted from the base station. Therefore, in this study, we propose a technology for relay transmission to users with poor communication conditions based on half-duplex cooperative NOMA using terrestrial amplification relays according to the user's location relationship and communication range of the base station and relay. Through numerical performance analyses of the ergodic channel capacity and outage probability, it was confirmed that compared to existing techniques, the proposed technique cannot only improve communication quality for users with poor communication conditions, but also expand the communication range for remote users.
