<p>The work proposes a solution to improve reliability, coverage, spectral efficiency, and energy efficiency for wireless communications by integrating advanced techniques such as energy harvesting, cooperative communication, cognitive radio, non-orthogonal multiple access (NOMA), and full-duplex. In the proposed system model, the close NOMA device capable of full-duplex and energy harvesting for improved energy and spectral efficiencies acts as an amplify-and-forward/decode-and-forward relay to extend coverage of a NOMA transmitter (or enhance reliability of a far NOMA user, which is challenged by distance and fading). For further improving spectral efficiency, the NOMA transmitter operates as a cognitive radio user. To validate the reliability of this system model, the system throughput is thoroughly analyzed for arbitrary fading. Various findings validate the effectiveness of the proposed system in comparison with benchmark wireless systems employing orthogonal multiple access.</p>