The Journal of China Universities of Posts and Telecommunications ›› 2022, Vol. 29 ›› Issue (1): 102-112.doi: 10.19682/j.cnki.1005-8885.2022.2011

• Networks • Previous Articles     Next Articles

Energy-efficient power allocation for NOMA heterogeneous networks with imperfect CSI

Song Xin, Huang Xue, Gao Yiming, Qian Haijun   

  1. School of Computer and Communication Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066000, China
  • Received:2021-05-11 Revised:2021-07-05 Accepted:2021-09-15 Online:2022-02-26 Published:2022-02-28
  • Contact: Corresponding author: Huang Xue
  • Supported by:
    This work was supported by the National Nature Science Foundation of China (61473066) and the Natural Science Foundation of Hebei Province (F2021501020).

Abstract: In this paper, an optimal user power allocation scheme is proposed to maximize the energy efficiency for downlink non-orthogonal multiple access (NOMA) heterogeneous networks (HetNets). Considering channel estimation errors and inter-user interference under imperfect channel state information (CSI), the energy efficiency optimization problem is formulated, which is non-deterministic polynomial (NP)-hard and non-convex. To cope with this intractable problem, the optimization problem is converted into a convex problem and address it by the Lagrangian dual method. However, it is difficult to obtain closed-form solutions since the variables are coupled with each other. Therefore, a Lagrangian and sub-gradient based algorithm is proposed. In the inner layer loop, optimal powers are derived by the sub-gradient method. In the outer layer loop, optimal Lagrangian dual variables are obtained. Simulation results show that the proposed algorithm can significantly improve energy efficiency compared with traditional power allocation algorithms.

Key words: heterogeneous networks, non-orthogonal multiple access, imperfect channel state information, power allocation

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