Power allocation scheme for downlink and uplink NOMA networks

Resource allocation problem is a key issue in multi-carrier non-orthogonal multiple access (NOMA) networks. Maximum access problem and power allocation problem are two important problems in resource allocation problem. In this study, two algorithms are proposed to solve the two problems for multi-carrier NOMA networks, namely mixed integer programming algorithm (MIPA) and dynamic power allocation algorithm (DPAA). In order to solve the maximum access problem, a MIPA is proposed in uplink multi-carrier NOMA networks. For the power allocation problem, a DPAA is proposed in downlink multi-carrier NOMA networks. Simulation results show that MIPA can increase the number of supported users compared to other schemes, DPAA can improve user data rate by increasing mean channel quality indicator and make power allocation more reasonable. According to DPAA, the gains of weighted sum-rate utility per subcarrier can be improved with the increase in the number of subcarriers. Simulation results also show that the proposed scheme is superior to reservation channel technique in terms of the probability of call dropping and probability of call blocking.