Cooperative Relaying in a Three User Downlink NOMA System Using Dynamic Power Allocation


  • Mwewa Mabumba

    Department of Electrical and Electronics Engineering, University of Zambia, P. O. Box 32379, Lusaka, Zambia

  • Simon Tembo

    Department of Electrical and Electronics Engineering, University of Zambia, P. O. Box 32379, Lusaka, Zambia

  • Lukumba Phiri

    Department of Engineering and ICT, School of Engineering, Information Communications University, P.O. Box 30226, Lusaka, Zambia

Received: 20 October 2023 | Revised: 15 November 2023 | Accepted: 17 November 2023 | Published Online: 21 November 2023


Non-orthogonal multiple access (NOMA) represents the latest addition to the array of multiple access techniques, enabling simultaneous servicing of multiple users within a singular resource block in terms of time, frequency, and code. A typical NOMA configuration comprises a base station along with proximate and distant users. The proximity users experience more favorable channel conditions in contrast to distant users, resulting in a compromised performance for the latter due to the less favorable channel conditions. When cooperative communication is integrated with NOMA, the overall system performance, including spectral efficiency and capacity, is further elevated. This study introduces a cooperative NOMA setup in the downlink, involving three users, and employs dynamic power allocation (DPA). Within this framework, User 2 acts as a relay, functioning under the decode-and-forward protocol, forwarding signals to both User 1 and User 3. This arrangement aims to bolster the performance of the user positioned farthest from the base station, who is adversely affected by weaker channel conditions. Theoretical and simulation outcomes reveal enhancements within the system’s performance.


NOMA, Cooperative NOMA, Decode and forward, Dynamic power allocation


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How to Cite

Mabumba, M., Tembo, S., & Phiri, L. (2023). Cooperative Relaying in a Three User Downlink NOMA System Using Dynamic Power Allocation. Semiconductor Science and Information Devices, 5(1), 26–32.


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