Covert Performance of NOMA System with Hardware Impairments in Nakagami Fading Channel
Yu, Xiangbin Shen, Keyu Rui, Yun Yan, Shihao Jia, Guoqing Guizani, Mohsen
Yu, Xiangbin
Shen, Keyu
Rui, Yun
Yan, Shihao
Jia, Guoqing
Guizani, Mohsen
Supervisor
Department
Machine Learning
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Type
Journal article
Date
2025
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Language
English
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Abstract
In this paper, the covert performance of the non-orthogonal multiple access (NOMA) system with random transmit power under hardware impairments over the Nakagami fading channel is investigated, where the stronger user serves as a covert user (Bob) and receives the secure message from the transmitter (Alice) under the cover of the weaker user (Carl). The transmission is monitored by a warden (Willie). To improve the covert performance, we randomize the transmit power of Alice, which is subject to a uniform distribution. Based on this, considering the randomness of covert user’s position, we derive the closed-form expressions of the average detection error probability (ADEP) respectively for the warden with instantaneous and statistical channel information. Then, the optimal detection threshold based on one-dimensional (1D) search method is presented for minimizing the ADEP. To simplify the optimal threshold, the suboptimal threshold with low complexity is also derived. Besides, the outage probability (OP) of the system is deduced for performance analysis and optimization. Under the constraints of covertness and reliability, the power allocation (PA) coefficient is optimized to minimize the OP of the covert user, and the 1D search scheme is proposed to obtain the optimal solution. Also, a suboptimal scheme is presented to reduce the complexity of the optimal scheme. Numerical results are presented to validate our theoretical analysis, and show that randomizing the transmit power can effectively improve the covert performance. Moreover, the system with two optimized thresholds can obtain lower ADEP than that with a fixed threshold, and the system with two optimized PA coefficients has a lower OP than that with a fixed PA.
Citation
X. Yu, K. Shen, Y. Rui, S. Yan, G. Jia and M. Guizani, "Covert Performance of NOMA System with Hardware Impairments in Nakagami Fading Channel," in IEEE Transactions on Wireless Communications, doi: 10.1109/TWC.2025.3531642
Source
IEEE Transactions on Wireless Communications
Conference
Keywords
NOMA, Probability, Power system reliability, Hardware, Wireless communication, Security, Interference, Fading channels, Complexity theory, Communication system security
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Publisher
IEEE