Non-orthogonal multiple access technology is widely studied as a candidate access technology for Next Generation mobile communications. In this paper, we propose a method to reduce the power consumption of the mobile stations and improve the overall data rate by using strong user relays for data transmission to users in the shadowing area for NR (Next Radio) downlink using power domain non-orthogonal multiple access technology. We propose a rational pairing scheme for users in the shadow zone and propose a new transmission scheme in which a paired strong user (with good channel gain) relays data to a weak user (with poor channel gain) in the shadow zone. We propose a shadow zone estimation method and a new power allocation scheme for a pair of users with relay communication and perform numerical analysis and simulation. The computational and simulation results verify that the proposed method can reduce the power consumption and increase the data rate compared to the previous methods.