On the Optimal Power Allocation and Performance Analysis for the HSIC-PA Aided Hybrid NOMA

Hybrid non-orthogonal multiple access (H-NOMA), which leverages the complementary advantages of orthogonal multiple access (OMA) and NOMA, has emerged as a promising technique for next-generation wireless networks. This paper investigates power allocation optimization for the OMA and NOMA time slots allocated to the opportunistic user in H-NOMA systems, aiming to overcome the limitations of conventional equal power allocation strategies. Specifically, we consider an H-NOMA scheme that integrates hybrid successive interference cancellation (HSIC) with power adaptation (PA), referred to as the HSIC-PA aided H-NOMA scheme. To better adapt to practical communication scenarios, distinct power coefficients are assigned to the OMA and NOMA time slots of the opportunistic user to maximize the achievable data rate. Closed-form expressions for the optimal power allocation coefficients are derived, and simulation results validate the accuracy and effectiveness of the theoretical analysis.