Reduction of Computational Time Complexity in PD-NOMA

This paper proposes a new receiver architecture for Power Domain Non-Orthogonal Multiple Access (PD-NOMA) systems in downlink communication with improved computational time complexity. The analytical model of the proposed architecture is established and discussed in detail. The experimental results are obtained and compared with the conventional model. The average computation time of all users is recorded and discussed. The proposed model records a significant improvement in time complexity, providing an average improvement of 26.44%, 76.87%, 84.84%,88.70%, and so on for the QPSK PD-NOMA receiver, and -8.17%, 65.50%, 78.73%, 84.60%, and so on for the 16-QAM PD-NOMA receiver for each user, compared to the conventional model, while offering identical BER performance. It is also observed that, unlike conventional PD-NOMA receivers, the computational time complexity of the proposed model decreases significantly as the number of users increases.