scholarly journals Cancel-Decode-Encode Processing on Two-Way Cooperative NOMA Schemes in Realistic Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Thu-Thuy Thi Dao ◽  
Pham Ngoc Son
Keyword(s):  
Interference Cancellation ◽  
Imperfect Information ◽  
Signal To Noise Ratio ◽  
Utilization Efficiency ◽  
System Throughput ◽  
Spectrum Utilization ◽  
Digital Network ◽  
Asymptotic Expressions ◽  
Outage Probabilities ◽  
Multiple Relay

This paper considers the effects of perfect/imperfect successive interference cancellation (SIC) and perfect/imperfect ` information (CSI) in a multiple-relay two-way cooperative network using nonorthogonal multiple access (NOMA) and digital network coding (DNC). In this model, a relay is selected by maximizing estimated channel gains to enhance the decoding capacity of the nearer source and minimize the collection time of imperfect CSI. Spectrum utilization efficiency is enhanced two times by a mixture of the SIC and DNC techniques at the selected relay (called as the SIC-2TS protocol). The system performance is considered through analysis of the exact and asymptotic expressions of the system outage probabilities and throughput. The major thing is exposed as the proposed SIC-2TS protocol can reach the best performance at optimal positions of the selected relay. Besides, the system throughput of the proposed protocol outperforms a SIC-utilized two-way relaying scheme without the DNC (called as the SIC-3TS protocol) and a conventional two-way scheme (called as the CONV-4TS protocol) for all signal-to-noise ratio regions. Lastly, the validity of the analytical expressions is verified by the Monte Carlo simulation results.

scholarly journals SIC-Coding Schemes for Underlay Two-Way Relaying Cognitive Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Pham Ngoc Son ◽  
Tran Trung Duy ◽  
Khuong Ho-Van
Keyword(s):  
Interference Cancellation ◽  
Performance Enhancement ◽  
Cognitive Networks ◽  
Superposition Coding ◽  
Secondary Sources ◽  
Coding Schemes ◽  
Power Domain ◽  
Digital Network ◽  
Outage Probabilities ◽  
Primary Receiver

In this paper, we propose an underlay two-way relaying scheme with the successive interference cancellation (SIC) solution in which two secondary sources transmit simultaneously their data to each other through secondary relays. The proposed scheme is operated in only two time slots and under an interference constraint of a primary receiver, denoted as the UTW-2TS scheme. In the UTW-2TS scheme, the secondary relays employ the SIC operation to decode successively the data from received broadcast signals and then encode these data by two techniques: digital network coding (DNC) enforced by XOR operations (denoted as the UTW-2TS-DNC protocol) and superposition coding (SC) enforced by power domain additions (denoted as the UTW-2TS-SC protocol). A selected secondary relay which subjects to maximize decoding capacities and to minimize collection time of channel state information in two protocols UTW-2TS-DNC and UTW-2TS-SC experiences residual interferences from imperfect SIC operations. Outage probabilities and throughputs are solved in terms of exact closed-form expressions to evaluate the system performance of the proposed protocols. Simulation and analysis results provide performance enhancement of the proposed protocols UTW-2TS-DNC and UTW-2TS-SC owing to increase the number of the cooperative secondary relays, the interference constraints, and the distances from the secondary network to the primary receiver. The best throughputs are pointed at optimal interference power allocation coefficients and optimal locations of the selected secondary relay. Considering the same power consumption, the UTW-2TS-DNC protocol outperforms the UTW-2TS-SC protocol. Finally, the simulation results are collected to confirm the exact analysis values of the outage probabilities and throughputs.

scholarly journals Performance Analysis of IQI Impaired Cooperative NOMA for 5G-Enabled Internet of Things

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hui Guo ◽  
Xuejiao Guo ◽  
Chao Deng ◽  
Shangqing Zhao
Keyword(s):  
Internet Of Things ◽  
Outage Probability ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Specific Power ◽  
High Signal ◽  
Quadrature Phase ◽  
Outage Probabilities ◽  
Iot Devices

This paper investigates the joint effects of in-phase and quadrature-phase imbalance (IQI) and imperfect successive interference cancellation (ipSIC) on the cooperative Internet of Things (IoT) nonorthogonal multiple access (NOMA) networks where the Nakagami-m fading channel is taken into account. The closed-form expressions of outage probability for the far and near IoT devices are derived to evaluate the outage behaviors. For deeper insights of the performance of the considered system, the approximate outage probability and diversity order in high signal-to-noise ratio (SNR) regime are obtained. In addition, we also analyze the throughput and energy efficiency to characterize the performance of the considered system. The simulation results demonstrate that, compared with IQI, ipSIC has a greater impact on the outage performance for the near-IoT-device of the considered system. Furthermore, we also find that the outage probabilities of IoT devices can be minimized by selecting a specific power allocation scheme.

scholarly journals I/Q Imbalance and Imperfect SIC on Two-Way Relay NOMA Systems

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 249 ◽  
Author(s):  
Xinji Tian ◽  
Qianqian Li ◽  
Xingwang Li ◽  
Hongxing Peng ◽  
Changsen Zhang ◽  
...  
Keyword(s):  
Outage Probability ◽  
Fading Channels ◽  
Interference Cancellation ◽  
Signal To Noise Ratio ◽  
High Reliability ◽  
System Throughput ◽  
Rician Fading ◽  
High Signal ◽  
Decode And Forward ◽  
Outage Performance

Non-orthogonal multiple access (NOMA) system can meet the demands of ultra-high data rate, ultra-low latency, ultra-high reliability and massive connectivity of user devices (UE). However, the performance of the NOMA system may be deteriorated by the hardware impairments. In this paper, the joint effects of in-phase and quadrature-phase imbalance (IQI) and imperfect successive interference cancellation (ipSIC) on the performance of two-way relay cooperative NOMA (TWR C-NOMA) networks over the Rician fading channels are studied, where two users exchange information via a decode-and-forward (DF) relay. In order to evaluate the performance of the considered network, analytical expressions for the outage probability of the two users, as well as the overall system throughput are derived. To obtain more insights, the asymptotic outage performance in the high signal-to-noise ratio (SNR) region and the diversity order are analysed and discussed. Throughout the paper, Monte Carlo simulations are provided to verify the accuracy of our analysis. The results show that IQI and ipSIC have significant deleterious effects on the outage performance. It is also demonstrated that the outage behaviours of the conventional OMA approach are worse than those of NOMA. In addition, it is found that residual interference signals (IS) can result in error floors for the outage probability and zero diversity orders. Finally, the system throughput can be limited by IQI and ipSIC, and the system throughput converges to a fixed constant in the high SNR region.

Development of mathematical model for multi-user coded-cooperation based cognitive radio system and its outage probability analysis

2021 ◽  
Author(s):  
Garima Singh ◽  
Gurjit Kaur
Keyword(s):  
Mathematical Model ◽  
Cognitive Radio ◽  
Outage Probability ◽  
Utilization Efficiency ◽  
Spectrum Efficiency ◽  
Spectrum Utilization ◽  
Radio System ◽  
Cognitive Radio System ◽  
Temperature Constraint ◽  
Coded Cooperation

Abstract In this paper, single and multi-user coded-cooperation based cognitive radio system is developed by designing its mathematical model where both source and relay will communicate to a single destination with the help of each other. Then all possible multi-user scenarios are developed and their end-to-end outage probability (Pout) is calculated for underlay mode of cognitive radio. The performance of the system is analyzed in the form of channel gain and interference temperature constraint for Rayleigh fading channel. The proposed system concludes that the coded cooperation with cognitive radio outperform the available techniques in the form of bandwidth, diversity, spectrum utilization efficiency and also improves the quality of communication. Furthermore, the theoretical analysis of the outage probability for both system models is validated by asymptotic analysis. The proposed system can set as a standard for all those cognitive radio applications which requires better spectrum efficiency even if there is a scarcity of multiple physical antennas.

scholarly journals Outage Performance Improvement by Selected User in D2D Transmission and Implementation of Cognitive Radio-Assisted NOMA

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4840
Author(s):  
Dinh-Thuan Do ◽  
Minh-Sang Van Nguyen ◽  
Byung Moo Lee
Keyword(s):  
Cognitive Radio ◽  
Fading Channels ◽  
Interference Cancellation ◽  
Rayleigh Fading ◽  
Positive Impact ◽  
System Model ◽  
Outage Performance ◽  
Secondary Network ◽  
Asymptotic Expressions ◽  
D2d Transmission

In this paper, we investigate the outage performance in secondary network of cognitive radio (CR) employing non-orthogonal multiple access (NOMA) wireless networks over Rayleigh fading channels. The considered system model adopts device-to-device (D2D) transmission together with traditional communication to form a new system model, namely CR-D2DNOMA network. The specific user is selected from multiple D2D-Tx users (D2Ds) to communicate with far NOMA users to form qualified D2D connection with assistance of the Relay user ( R U ). The main metric in such CR-D2DNOMA network needs to be considered and we particularly introduce the closed-form expressions for outage probability in the secondary network where it is designed to serve two far NOMA users. The perfect Successive Interference Cancellation (SIC) and imperfect SIC can be further examined at the second NOMA user who detects signal based on the ability of SIC. The results show the positive impact of increasing the fading parameters on the system performance. More importantly, numerical results are provided to verify the correctness of our derivations. Additionally, the effects of asymptotic expressions on insights evaluation are also further analyzed.

scholarly journals Performance Analysis of Full-Duplex Amplify-and-Forward Relay System with Hardware Impairments and Imperfect Self-Interference Cancellation

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ba Cao Nguyen ◽  
Xuan Nam Tran
Keyword(s):  
Interference Cancellation ◽  
Signal To Noise Ratio ◽  
Relay Node ◽  
Analytical Framework ◽  
Full Duplex ◽  
High Signal ◽  
Amplify And Forward ◽  
Relay System ◽  
Hardware Impairments ◽  
The Impact

In this paper, we analyze the performance of a full-duplex (FD) amplify-and-forward (AF) relay system with imperfect hardware. Besides the aggregate hardware impairments of the imperfect transceiver, we also consider the impact of residual self-interference (RSI) due to imperfect cancellation at the FD relay node. An analytical framework for analyzing the system performance including exact outage probability (OP), asymptotic OP, and approximate symbol error probability (SEP) is developed. In order to tackle these impacts, we propose an optimal power allocation scheme which can improve the outage performance of the FD relay node, especially at the high signal-to-noise ratio (SNR) regime. Numerical results are presented for various evaluation scenarios and verified using the Monte Carlo simulations.

scholarly journals Outage Analysis of Parasitic Ambient Backscatter Communication in Decode-and-Forward Relay Networks with SWIPT

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1273
Author(s):  
Yanhong Tuo ◽  
Chao Zhang
Keyword(s):  
Interference Cancellation ◽  
Primary Source ◽  
Relay Networks ◽  
Power Splitting ◽  
Decode And Forward ◽  
Backscatter Communication ◽  
Rf Signals ◽  
Outage Probabilities ◽  
The One ◽  
The Cost

In this paper, we investigate the outage performance of simultaneous wireless information and power transfer (SWIPT) based Decode-and-Forward (DF) relay networks, where the relay needs to simultaneously forward information for two relaying links, primary relaying link and parasitic relaying link. The primary relaying link is the traditional source-relay-destination relay system. While in the parasitic relaying link, the parasitic source, i.e., Internet-of-Things (IoT) tag, is not connected to the stable power source and thus has to backscatter the signals from the primary source to convey its information. The relay not only harvests energy from Radio Frequency (RF) signals from both sources but also forwards messages to their corresponding destinations. The primary source and destination are unaware of the parasitic backscatter transmission, but the relay and parasitic destination can employ successive interference cancellation (SIC) detector to eliminate the interference from the primary link and detect the message from the parasitic source. In order to investigate the interplay between the primary and parasitic relaying links, the outage probabilities of both relaying links are derived. Besides, the effects of system parameters, i.e., power splitting coefficient, forwarding power allocation coefficient and backscatter reflection coefficient, on the system performance are discussed. Simulation results verify our theoretical analysis. In the meanwhile, it is revealed that the advised relaying system has far larger sum throughput than the one with only primary relaying link and the parasitic relaying link can gain considerable throughput at the cost of negligible degradation of primary throughput.

A Novel QoS Guaranteed Cross-Layer Scheduling Scheme for Downlink Multiuser OFDM Systems

2012 ◽  
Vol 182-183 ◽  
pp. 1352-1357 ◽  
Author(s):  
Wen Min Ma ◽  
Hai Jun Zhang ◽  
Xiang Ming Wen ◽  
Wei Zheng ◽  
Zhao Ming Lu
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Optimization Problem ◽  
System Throughput ◽  
Cross Layer ◽  
Ofdm Systems ◽  
Spectrum Utilization ◽  
Scheduling Scheme ◽  
Qos Differentiation ◽  
Efficient Power

To provide quality-of-service (QoS) differentiation and guarantee user fairness, efficient power and spectrum utilization for the downlink multiuser orthogonal frequency-division multiplexing (MU-OFDM) systems, a novel QoS guaranteed cross-layer (QGCL) scheduling scheme is proposed in this paper. The scheme formulates the scheduling into an optimization problem of overall system utility under the system constraints. Moreover, we propose a simple and efficient binary constrained particle swarm optimization (PSO) to solve the scheduling more effectively. Comparing with the classical methods, simulation results show that the proposed QGCL scheduling scheme can significantly maximize the system throughput given that the fulfillment of the QoS requirements as well as the fairness is guaranteed.

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