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http://dx.doi.org/10.7236/JIIBC.2017.17.5.25

Optimum Power Allocation of Cooperative NOMA Systems based on User Relay  

Kim, Nam-Soo (Dept. of Electronic Engineering, Cheongju University)
Publication Information
The Journal of the Institute of Internet, Broadcasting and Communication / v.17, no.5, 2017 , pp. 25-33 More about this Journal
Abstract
NOMA (Non-orthogonal multiple access) system becoming a strong candidate for 5G cellular system of its high spectral efficiency. This paper considers an optimal power allocation scheme to minimize the outage probability of a user relay based cooperative NOMA system. We first derive the outage probabilities of the relay user (RU) and the destination user (DU) with selection combining. Based on these probabilities, the outage probability of the cooperative NOMA system is obtained. The analytical results are verified by Monte Carlo simulation. It is noticed that the outage probability of cooperative NOMA system has a convex function, the optimum power allocation coefficient, which satisfied the minimum outage probability, is calculated. Numerical examples show that the optimal power allocation coefficient increases with the required capacity of DU. While the capacity of DU is fixed, we noticed that the increase of the required capacity of RU decreases the optimal power allocation coefficient.
Keywords
NOMA; Cooperative NOMA; User relay; Power allocation;
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Times Cited By KSCI : 1  (Citation Analysis)
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