An Efficient Hybrid Energy Harvesting Protocol for Cooperative NOMA Systems: Error and Outage Performance

Abstract

Cooperative non-orthogonal multiple access (CNOMA) has been recently adapted with energy harvesting (EH) to increase energy efficiency and extend the lifetime of energy-constrained wireless networks. In EH, two protocols are usually used for CNOMA, namely, power splitting (PS) and time switching (TS). In order to improve the existing EH protocols, this paper investigates a hybrid EH protocol-assisted CNOMA, which is a combination of the two aforementioned main existing EH protocols. The end-to-end bit error rate (BER) and outage probability (OP) expressions of users in our scheme are derived over Nakagami-m fading channels. For the sake of comparison and to highlight the achievable gains, the performance of the hybrid EH (HEH) protocol is compared with the benchmark schemes (i.e., existing EH protocols and no-EH). Based on extensive simulations, it is shown that the analytical results match perfectly with simulations which demonstrates the correctness of the derivations. Numerical results clearly indicate the superiority of the proposed scheme over all the considered benchmarks. In addition, we discuss the optimum value of EH factors to minimize the error and outage in the proposed scheme and show that an optimum value can be obtained according to channel parameters.

Nonorthogonal multiple access multiple input multiple output communications with harvested energy: Performance evaluation

“…where (11) handles the D2's outage, Δ 2n ¼ 1, when the target spectral efficiency, K, EH duration, ν, and power-splitting factor, ψ, are configured improperly, where Λ 0 ≥ ψ=ð1 À ψÞ.…”

“…Comment 3: Equations ( 9) and (11) show that the OP of Dd is contingent on multiple specifications: K, ν, ψ, P, N B , N S , N 1 , N 2 , Ω, and τ. Thus, target performance can be attained by appropriately configuring these specifications.…”

“…Notably, 5G/6G users are already equipped with affordable energy harvesting (EH) circuits [5,6]. Interestingly, the literature has focused only on the linear EH (lEH) characteristics needed to analyze basic system performance [7][8][9][10][11][12]. However, EH circuits comprise non-linear components, such as capacitors, diodes, and inductors.…”