Power allocation‐Assisted secrecy analysis for NOMA enabled cooperative network under multiple eavesdroppers

Abstract

In this work, the secrecy of a typical wireless cooperative dual‐hop non‐orthogonal multiple access (NOMA)‐enabled decode‐and‐forward (DF) relay network is investigated with the impact of collaborative and non‐collaborative eavesdropping. The system model consists of a source that broadcasts the multiplexed signal to two NOMA users via a DF relay, and information security against the eavesdropper nodes is provided by a helpful jammer. The performance metric is secrecy rate and ergodic secrecy capacity is approximated analytically. In addition, a differential evolution algorithm‐based power allocation scheme is proposed to find the optimal power allocation factors for relay, jammer, and NOMA users by employing different jamming schemes. Furthermore, the secrecy rate analysis is validated at the NOMA users by adopting different jamming schemes such as without jamming (WJ) or conventional relaying, jamming (J), and with control jamming (CJ). Simulation results demonstrate the superiority of CJ over the J and WJ schemes. Finally, the proposed power allocation outperforms the fixed power allocation under all conditions considered in this work.

Optimal Resource Allocation for NOMA Wireless Networks

“…For the research on the power allocation algorithm in the NOMA system, the objective function is mainly focused on minimizing the total transmit power [9][10][11][12][13], minimizing the probability of outage [14][15][16][17], and maximizing system throughput [18][19][20], etc. The main existing algorithms full search power allocation (FSPA) [21], fixed power allocation (FPA) [22], iterative water-filling power allocation (IWPA) [23], and fractional transmit power allocation (FTPA) [24].…”