Effective Resource Utilization Schemes for Decode-and-Forward Relay Networks With NOMA

Abstract

This paper investigates an effective resource utilization scheme for the decode-and-forward (DF) cooperative relaying networks (CRNs) with non-orthogonal multiple access (NOMA). Considering a T time slots transmission, the proposed effective resource utilization scheme adopts max-min relay selections to satisfy the quality-of-service (QoS) and provide a higher priority. Unlike the conventional CRNs, to improve the system performance and resource utilization, the unselected relays will continue receiving the signals transmitted by the base station (BS), as well as the selected relays forward the decoded signals to the user equipment (UE). Moreover, the maximum ratio combining (MRC) is utilized at the UE to jointly detect the receptions for each time slot. The achievable average sum-rate (SR) of the proposed system is analyzed for independent Rayleigh fading channels, and the asymptotic expressions are also provided. The qualitative numerical results corroborating our theoretical analysis show that the proposed effective resource utilization scheme significantly improves the transmission rate and SR performance in comparison to the conventional CRN-NOMA schemes. INDEX TERMS Non-orthogonal multiple access (NOMA), cooperative relaying networks (CRN), ergodic sum-rate (SR), decode-and-forward (DF), quality-of-service (QoS).

Distributed differential beamforming and power allocation for cooperative communication networks

“…where 1 ( ) and 2 ( ) are the noise signals at the two terminals 1 2 in respect to the ℎ block. Given the high SNR in (12) and (13), those two equations can be rewritten as:…”

“…Differential modulation has recently received considerable interest as it offers diversity and coding gain without the need for channel estimation [1][2][3][4][5][6][7][8]. Relaying techniques for wireless communication systems have been studied extensively in the last decade [9][10][11][12][13][14][15][16]. They have proposed many promising features such as high data rates, and better capacity.…”

Joint Power Allocation for NOMA-Based Diamond Relay Networks With and Without Cooperation

“…Later, the key features, opportunities, and challenges of this kind of cooperative NOMA networks are reviewed and summarized in [14]. The authors in [15]- [18] considered the relay selection problem in NOMA-based relay networks, while those in [19]- [22] examined the related power-allocation problem. In practice, both problems are of great importance since the relay location and power allocation both have a significant effect on the NOMA/relaying behavior, and thus also impact the overall performance of the network.…”

“…The authors in [19] consider a new way for selecting an optimal relay mode and optimal transmission power levels simultaneously in NOMA-based relay networks to achieve a better network throughput. Furthermore, the spectral efficiency of amplify-and-forward (AF)-based NOMA cooperation is investigated in [20], while a similar problem is tackled for decode-and-forward (DF)-based NOMA cooperation as well in [22]. The problem of joint resource allocation, involving the subcarrier pair, subcarrier-user assignment, and power levels, is examined to maximize the network throughput in [21].…”

Performance Analysis of Power-Splitting Relaying Protocol in SWIPT Based Cooperative NOMA Systems

“…There are two main data forwarding schemes in relay-assisted C-NOMA, including decode-and-forward (DF) and amplify-and-forward (AF) [1]. Furthermore, in relay based C-NOMA, far users normally receive the transmitted signal which is forwarded from relay nodes [23]- [27]. This is because there are some obstacles on the propagation [5]- [6], [28].…”