Skip to main content

Decode-and-Forward Relaying for Cooperative NOMA Systems With Direct Links

Author(s): Liu, Hongwu; Ding, Zhiguo; Kim, Kyeong Jin; Kwak, Kyung Sup; Poor, H Vincent

To refer to this page use:
Abstract: This paper investigates a cooperative non-orthogonal multiple access system, in which a base station communicates with two far users with the aid of a decode-and-forward (DF) relay. Three cooperative relaying schemes, namely, the fixed relaying (FR), the selective DF with coordinated direct and relay transmission (SDF-CDRT), and the incremental-selective DF (ISDF) relaying are proposed to enhance the outage performance for the two far users by utilizing both the direct and relay links. Taking into account the received signal-to-noise ratio (SNR) events at the relay, the SDF-CDRT scheme adaptively forms an orthogonal transmission branch with respect to the direct link or keeps silent to reduce error propagation. Besides considering the relay detection results, the ISDF scheme further exploits the limited feedback of the received SNR events from two users, so that error propagation can be avoided and unnecessary relaying can be reduced. Analytical expressions for the outage probabilities and average throughputs of the paired users are derived in closed-form for the three cooperative relaying schemes. Asymptotic expressions for the outage probabilities are derived in the high SNR region. It is shown that the FR and SDF-CDRT schemes achieve a diversity order of one for both users, while the ISDF scheme achieves a diversity order of two for both users. The superior system performance achieved by the proposed schemes over those of the existing methods is verified by Monte Carlo simulations.
Publication Date: 11-Oct-2018
Citation: Liu, Hongwu, Ding, Zhiguo, Kim, Kyeong Jin, Kwak, Kyung Sup, Poor, H Vincent. (2018). Decode-and-Forward Relaying for Cooperative NOMA Systems With Direct Links. IEEE Transactions on Wireless Communications, 17 (12), 8077 - 8093. doi:10.1109/twc.2018.2873999
DOI: doi:10.1109/twc.2018.2873999
ISSN: 1536-1276
EISSN: 1558-2248
Pages: 8077 - 8093
Type of Material: Journal Article
Journal/Proceeding Title: IEEE Transactions on Wireless Communications
Version: Author's manuscript

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.