scholarly journals Cooperative Non-Orthogonal Multiple Access over Log-Normal Power Line Communication Channels

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1254
Author(s):  
Roger Kwao Ahiadormey ◽  
Prince Anokye ◽  
Kyoung-Jae Lee
Keyword(s):  
Outage Probability ◽  
Multiple Access ◽  
Power Line ◽  
System Throughput ◽  
Power Line Communication ◽  
High Signal ◽  
Second Phase ◽  
Power Domain ◽  
Log Normal ◽  
The Impact

In this paper, we analyze the performance of cooperative power domain non-orthogonal multiple access (NOMA) in power line communication (PLC) networks. Due to the high signal attenuation of the source to user links, a relay aids communication from the source to two users. With half-duplex transmission, the source transmits a superimposed symbol in the first phase. The relay utilizes amplify-and-forward (AF) and decode-and-forward (DF) protocol on the received superimposed signal and forwards it to the users in the second phase. We derive analytic expressions for the outage probability and the system throughput of the proposed system under a PLC log-normal channel with impulsive noise. Based on the results for AF NOMA relaying case, we analyze the system performance at high signal-to-noise ratio (SNR) and derive closed-form lower and upper bounds for the outage probability. Simulation results show an improvement in the outage probability and the system throughput performance of the AF and DF NOMA schemes compared to the NOMA without relaying transmission and conventional orthogonal multiple access scheme. Furthermore, the impact of the channel variance is highlighted in the results. It is shown that the DF NOMA has a better outage probability than the AF NOMA scheme for low channel variance scenarios (i.e., less branches and connected loads in the PLC network). However, as the channel variance increases, AF NOMA scheme has similar outage probability performance as the DF NOMA scheme. In addition, it is shown that the system throughput is enhanced when the relay employs DF relaying compared to AF relaying.

scholarly journals Throughput and Outage Probability Analysis for Cognitive Radio-Non-Orthogonal Multiple Access in Uplink and Downlink Scenarios

2020 ◽  
Vol 7 (4) ◽  
pp. 659-666
Author(s):  
H.T. Madan ◽  
Prabhugoud I. Basarkod
Keyword(s):  
Cognitive Radio ◽  
Outage Probability ◽  
Power Allocation ◽  
Cognitive Radio Networks ◽  
Multiple Access ◽  
Radio Networks ◽  
Spectrum Efficiency ◽  
Secondary Users ◽  
Power Domain ◽  
The Impact

Non orthogonal multiple access (NOMA) in cognitive radio (CR) network has been recognized as potential solution to support the simultaneous transmission of both primary and secondary users. In addition, CR-NOMA can also be used to serve multiple secondary networks in overlay cognitive radio networks. The aim of our work is to increase the secondary user’s throughput without compromising in QoS requirements of the primary users. Our presented work analyses the performance of power domain NOMA in cognitive radio networks for both uplink and downlink scenarios. The primary aspect of the work is to investigate the impact of power allocation on spectrum efficiency and fairness performance of CR-NOMA. Objective function is to maximize the overall throughput under the QOS constraints of the users. We have derived closed form expressions for optimized power allocation coefficient(α) for CR-NOMA uplink and downlink communications. Parameters causing the channel outage, have been examined and conditions for outage probability is derived for CR-NOMA communication. Finally, we have presented the simulation results to validate the mathematical models that are developed for power allocation coefficient and outage probability.

scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Youssef Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Ahmed Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Youssef Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

Outage Performance Analysis for User Cooperative NOMA with Incremental Hybrid Forwarding Protocols

2021 ◽  
Author(s):  
Suyue Li ◽  
Junhuai Liu ◽  
Anhong Wang
Keyword(s):  
Monte Carlo ◽  
Outage Probability ◽  
Multiple Access ◽  
System Throughput ◽  
Closed Form Expression ◽  
Collaborative Communication ◽  
Form Expression ◽  
Outage Performance ◽  
Threshold Rate ◽  
Rate Pair

Abstract Non-orthogonal multiple access (NOMA) collaborative communication is extremely beneficial to the users with poor channel conditions. It is essential to examine the performance of different NOMA users with superior cooperative forwarding protocols. This paper addresses the user cooperative NOMA system where one strong user (U2) assists one weak user (U1) to forward messages, and investigates the outage performance of both users with hybrid decode-and-amplify forwarding (HDAF) protocol. First, we derive the outage probability of U2 and U1 with HDAF. Secondly, we provide the closed-form expression for outage probability of U1 with the incremental hybrid decode-and-amplify forward (IHDAF) protocol at U2, which can further enhance the outage performance of U1 compared with HDAF. Moreover, we also present the system throughput expression and provide deep analysis on the effect of different forwarding protocols. Numerical results and Monte Carlo simulations jointly confirm the correctness of all the analytic derivations. In addition to saving the energy consumption of U2, IHDAF can make U1 achieve superior outage performance to HDAF. However, the system throughput almost overlap for both schemes given a threshold rate pair.

scholarly journals Time Switching Based Wireless Powered Relay Transmission with Uplink NOMA

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5467
Author(s):  
Zhihua Lin ◽  
Shihua Cao ◽  
Jianqing Li
Keyword(s):  
Multiple Access ◽  
Relay Node ◽  
Base Station ◽  
Spectrum Efficiency ◽  
Transmission Model ◽  
System Throughput ◽  
Time Switching ◽  
Power Domain ◽  
End Node ◽  
Save Energy

Non-orthogonal multiple access (NOMA) utilizes power domain multiplexing to improve spectrum efficiency compared with orthogonal multiple access (OMA). In the Internet of Things (IoT) uplink NOMA networks, if the channel between the far-end node and the base station is in deep fading, allocating larger transmitting power for this node cannot achieve higher spectrum efficiency and overall system throughput. Relay cooperative communication reduces the transmitting power at the far-end node but leads to extra energy expenditure at the relay node. Fortunately, simultaneous wireless information and power transfer (SWIPT) is advocated in energy-constrained IoT networks to save energy consumption. However, early works all focus on energy harvesting (EH) from one source node or one dedicated power supply station. In this paper, we propose a time switching based wireless powered relay transmission model with uplink NOMA where our EH technique can harvest energy from two simultaneously transmitting nodes. More importantly, by optimizing relay position more energy is harvested from the near-end node at the relay and relay signal attenuation to the destination is reduced as well. Furthermore, the closed-form expressions of outage probability and overall system throughput are derived, and numerical results prove that NOMA in our EH scheme achieves better performance compared to the traditional EH scheme and OMA by optimizing the position of the relay node, time switching factor and so on.

scholarly journals Massive MIMO-NOMA Networks with Imperfect SIC: Design and Fairness Enhancement

2020 ◽  
Author(s):  
Arthur Sousa de Sena ◽  
Pedro Nardelli
Keyword(s):  
Outage Probability ◽  
Power Allocation ◽  
Interference Cancellation ◽  
Massive Mimo ◽  
Multiple Access ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Optimal Solution ◽  
Input Multiple Output ◽  
The Impact

This paper addresses multi-user multi-cluster massive multiple-input-multiple-output (MIMO) systems with non-orthogonal multiple access (NOMA). Assuming the downlink mode, and taking into consideration the impact of imperfect successive interference cancellation (SIC), an in-depth analytical analysis is carried out, in which closed-form expressions for the outage probability and ergodic rates are derived. Subsequently, the power allocation coefficients of users within each sub-group are optimized to maximize fairness. The considered power optimization is simplified to a convex problem, which makes it possible to obtain the optimal solution via Karush-Kuhn-Tucker (KKT) conditions. Based on the achieved solution, we propose an iterative algorithm to provide fairness also among different sub-groups. Simulation results alongside with insightful discussions are provided to investigate the impact of imperfect SIC and demonstrate the fairness superiority of the proposed dynamic power allocation policies. For example, our results show that if the residual error propagation levels are high, the employment of orthogonal multiple access (OMA) is always preferable than NOMA. It is also shown that the proposed power allocation outperforms conventional massive MIMO-NOMA setups operating with fixed power allocation strategies in terms of outage probability.

scholarly journals Fundamental Limits on the Uplink Performance of the Dynamic-Ordered Successive Interference Cancellation Receiver

2021 ◽  
Author(s):  
Luca Lusvarghi ◽  
Maria Luisa Merani
Keyword(s):  
System Performance ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Rayleigh Fading ◽  
Analytical Approach ◽  
Successive Interference Cancellation ◽  
Fundamental Limits ◽  
Power Domain ◽  
Lognormal Shadowing ◽  
The Impact

<div>This work puts forth a novel analytical approach to evaluate the performance that power-domain Non-Orthogonal Multiple Access (NOMA) achieves on the uplink of a single cell. A dynamic-ordered Successive Interference Cancellation (SIC) receiver is considered, and both the case of Rayleigh and lognormal-shadowed Rayleigh fading are examined. System performance is assessed analytically, deriving either exact or approximated closed-form expressions, whose correctness and excellent accuracy are validated through Monte Carlo simulations. The analysis discloses the effects on performance of an arbitrary number n of simultaneously transmitting users, therefore unveiling where the insourmountable limits of the dynamic-ordered SIC receiver lie. Moreover, the proposed methodology allows to quantify</div><div>the impact of lognormal shadowing on NOMA efficacy. </div>

scholarly journals Performance Analysis of MEC Based on NOMA under Imperfect CSI with Eavesdropper

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xuehua Li ◽  
Yingjie Pei ◽  
Huan Jiang ◽  
Xinwei Yue ◽  
Yafei Wang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Channel State Information ◽  
Multiple Access ◽  
System Throughput ◽  
Secrecy Outage Probability ◽  
Imperfect Csi ◽  
Channel State ◽  
State Information ◽  
Secrecy Outage ◽  
The Impact

Mobile edge computing (MEC) is becoming more and more popular because of improving computing power in virtual reality, augmented reality, unmanned driving, and other fields. This paper investigates a nonorthogonal multiple access- (NOMA-) based MEC system, which is under imperfect channel state information (ipCSI). In this system model, a pair of users offloads their tasks to the MEC server with the existence of an eavesdropper (Eve). To evaluate the impact of Eve on the performance of the NOMA-MEC system, the secrecy outage probability (SOP) expressions for two users with the conditions of imperfect CSI and perfect channel state information (pCSI) are derived. In addition, both throughput and energy efficiency are discussed in the delay-limited transmission mode. Simulation results reveal that (1) due to the influence of channel estimation errors, the secrecy outage behaviors of two users under ipCSI conditions are worse than those of users with pCSI; (2) the secrecy performance of NOMA-MEC is superior to orthogonal multiple access- (OMA-) aided MEC systems; and (3) the NOMA-MEC systems have the ability to attain better system throughput and energy efficiency compared with OMA-MEC.

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