Abstract
In this paper, an enhanced transmission scheme for cooperative relaying networks with non-orthogonal multiple access (ECRN-NOMA) is proposed. In the proposed scheme, two different kinds of transmission schemes are investigated which are the single signal transmission and the enhanced superposition transmission schemes. Particularly, for the single transmission scheme, a successive interference cancellation (SIC) is utilized to decode the received signal, sent by the relay, at the destination. On the other hand, for the enhanced superposition coded signal transmission scheme, a maximum ratio combining (MRC) is utilized at the destination to improve the ergodic sum-rate (SR) of the proposed system. Specifically, two power allocation (PA) strategies are comprehensively discussed to characterize the performance of our proposed scheme. The achievable average SR of the proposed systems are analyzed for independent Rayleigh fading channels, and also their asymptotic expressions are also provided. Qualitative numerical results corroborating our theoretical analysis show that the enhanced superposition coded signal transmission scheme applied to the proposed ECRN-NOMA improves the SR performance significantly in comparison to the others.
Highlights
1 Introduction A non-orthogonal multiple access (NOMA) technique has been widely considered as a promising multiple access (MA) potential candidate for future wireless networks due to its superior spectral efficiency [1, 2]
In order to further improve the ergodic SR, we comprehensively investigate an enhanced 2-stage superposed transmission scheme for Cooperative relay networks (CRN)-NOMA with two relays is considered, where, unlike existing works, the source and the relays are allowed to transmit superposition-coded signals, which is more general and challenging
4 Numerical results we examine the performance of our proposed CTRS-NOMA schemes in terms of the ergodic SR
Summary
A non-orthogonal multiple access (NOMA) technique has been widely considered as a promising multiple access (MA) potential candidate for future wireless networks due to its superior spectral efficiency [1, 2]. For the CTRS-NOMA single case, we discussed two kinds of the power allocation schemes, i.e., for relay nodes i, the transmitted symbol xi is allocated with a higher PA factor for case I, while a lower PA factor for case II In this manner, the proposed CTRS-NOMA single case contains all the possible transmission strategies, which is necessary to employ two relays to support that of the strategies. The proposed scheme is possible to provide the mentality to study the multi-relaying systems and applicable in the future cooperative NOMA networks. These motivate us to investigate an enhanced transmission scheme with two relays.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call