Статті в журналах з теми "Amplify-and-forward (AF) and decode-and-forward (DF) cooperative communication"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Amplify-and-forward (AF) and decode-and-forward (DF) cooperative communication.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-33 статей у журналах для дослідження на тему "Amplify-and-forward (AF) and decode-and-forward (DF) cooperative communication".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Sehito, Nabila, Shouyi Yang, Abdullh G. Al Harbi, Muhammad Inam Abbasi, Muhammad Abbas Khan, Muhammad Amir Khan, and Mian Muhammad Kamal. "Secrecy Performance by Power Splitting in Cooperative Dual-Hop Relay Wireless Energy Harvesting." Wireless Communications and Mobile Computing 2022 (May 14, 2022): 1–7. http://dx.doi.org/10.1155/2022/8367107.
Повний текст джерелаАнотація:
In wireless communication systems, for secure communication between a transmitter and receiver over the communication channel, the physical layer security is widely utilized. The paper presents a dual-hop wireless full-duplex relay (FDR) network with a source relay and destination relay between two nodes and listening devices. The relay and source use energy harvesting to gain energy from power beacon. Two cooperative techniques are utilized to investigate the amplify-forward (AF) and decode-forward (DF) secrecy capacity in the energy harvesting power splitting system. It is shown that the secrecy performance of an AF relay is better than the secrecy performance of a DF relay in the given form. At 40-meter distance between the relay and the eavesdropper in an energy harvesting system, the AF relay outperforms the DF relay. The simulation is performed using the Monte-Carlo method in MATLAB.
2
Ahiadormey, Roger Kwao, Prince Anokye, and Kyoung-Jae Lee. "Cooperative Non-Orthogonal Multiple Access over Log-Normal Power Line Communication Channels." Electronics 8, no. 11 (November 1, 2019): 1254. http://dx.doi.org/10.3390/electronics8111254.
Повний текст джерелаАнотація:
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.
3
Kim, Seung-Hwan, Jae-Woo Kim, and Dong-Seong Kim. "Energy Consumption Analysis of Beamforming and Cooperative Schemes for Aircraft Wireless Sensor Networks." Applied Sciences 10, no. 12 (June 25, 2020): 4374. http://dx.doi.org/10.3390/app10124374.
Повний текст джерелаАнотація:
In this paper, the eight schemes for aircraft wireless sensor networks are investigated, which are single-hop array beamforming schemes (including analog beamforming (ABF), and digital beamforming (DBF)), non-cooperative schemes (including single-hop and multi-hop schemes), cooperative schemes (including amplify and forward (AF), decode and forward (DF)), and incremental cooperative schemes (incremental decode and forward (IDF), and incremental amplify and forward (IAF)). To set up the aircraft wireless communication environment, we design the aircraft channel model by referring to the experimental parameters of the ITU (International Telecommunication Union)-R M.2283, which is composed of path loss, shadowing fading, and multi-path fading channel responses. To evaluate the performance, the conditions energy consumption and throughput analysis are performed. Through simulation results, the incremental cooperative scheme outperformed by 66.8% better at spectral efficiency 2 than the DBF scheme in terms of the energy consumption metric. Whereas, in terms of throughput metric, overall SNR (signal-to-noise ratio) ranged from −20 to 30 dB the beamforming scheme had the best performance in which the beamforming scheme at SNR 0 dB achieved 85.4% better than the multi-hop scheme. Finally, in terms of normalized throughput metric in low SNR range between −20 and 1 dB the ABF scheme had the best performance over the others in which the ABF at SNR 0 dB achieved 75.4% better than the multi-hop scheme. Whereas, in high SNR range between 2 and 30 dB the IDF scheme had the best performance in which the IDF at SNR 10 dB achieved 62.2% better than the multi-hop scheme.
4
Yu, Meng, Jing (Tiffany) Li, and Hamid Sadjadpour. "A Geometry-Inclusive Analysis for Single-Relay Systems." International Journal of Digital Multimedia Broadcasting 2009 (2009): 1–9. http://dx.doi.org/10.1155/2009/146578.
Повний текст джерелаАнотація:
Successful message relay, or the quality of the interuser channel, is critical to fully realize the cooperative benefits promised by the theory. This in turn points out the importance of the geometry of cooperative system. This paper investigates the impact of the relay's location on the system capacity and outage probability for both amplify-forward (AF) and decode-forward (DF) schemes. Signal attenuation is modeled using power laws, and capacity is evaluated using the max-flow min-cut theory. A capacity contour for DF, the more popular mode of the two, is provided to facilitate the derivation of engineering rules. Finally, a selective single-relay system, which selects the best relay node among a host of candidates according to their locations, is analyzed. The average system capacity and outage, averaged over all possible candidates' locations, are evaluated. The result shows that the availability of a small candidate pool of 3 to 5 nodes suffices to reap most of the cooperative gains promised by a selective single-relay system.
5
Al Junaedi, Anas Machfudy, Sholeh Hadi Pramono, and M. Fauzan Edy Purnomo. "Performance Analysis of Intelligent Reflecting Surfaces in Multi-Input-Single-Output Indoor Hotspot Environment." International Journal of Computer Applications Technology and Research 10, no. 12 (December 2021): 261–66. http://dx.doi.org/10.7753/ijcatr1012.1001.
Повний текст джерелаАнотація:
The evolution of 5G and beyond is boosting the development of telecommunication technology. In the future communication system, achievable rate and energy efficiency become the main aspects due to highly reliable and low latency requirements. Applying multiple antennas and applying cooperative communication scenarios to the system may enhance the network's performance. Intelligent reflecting surfaces (IRS) and relaying protocols are some examples of cooperative communication applications. IRS is multiple two-dimensional meta-surface elements that can reflect the incoming signal to get the desirable beam-forming based on its phase. While the relay is a device that can be used to enhance the performance of the networks based on its protocols such as amplify forward (AF) and decode forward (DF). Accordingly, this paper studies an IRS supporting MISO transmission and compares it with the relay deployment scenario. As a result, IRS has higher performance compared with any other scenario, and adding more IRS elements may enhance the achievable rate.
6
Sehito, Nabila, Shouyi Yang, Esraa Mousa Ali, Muhammad Abbas Khan, Raja Sohail Ahmed Larik, Inam Bari, Mian Muhammad Kamal, Salahuddin Khan, Mohammad Alibakhshikenari, and Ernesto Limiti. "Physical Layer Secrecy by Power Splitting and Jamming in Cooperative Multiple Relay Based on Energy Harvesting in Full-Duplex Network." Electronics 11, no. 1 (December 23, 2021): 40. http://dx.doi.org/10.3390/electronics11010040.
Повний текст джерелаАнотація:
In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). In the presence of one eavesdropper, a signal is transferred from source to destination with the help of a relay. The source signal transmits in full-duplex (FD) mood, jamming the relay transfer signals to the destination. The relay and source employ Time Switching (TS) and Energy Harvesting (EH) techniques to obtain the power from the power beacon. In this study, we compared the Secrecy Rate of two Cooperative Schemes, Amplify and Forward (AF) and Decode and Forward (DF), for both designed systems with the established EH and PS system. The Secrecy Rate was improved by 50.5% in the AF scheme and by 44.2% in the DF scheme between the relay and eavesdropper at 40 m apart for the proposed system in EH and PS. This simulation was performed using the Monto Carlo method in MATLAB.
7
Wang, Zhenling, Zhangyou Peng, Yongsheng Pei, and Haojia Wang. "Performance Analysis of Cooperative NOMA Systems with Incremental Relaying." Wireless Communications and Mobile Computing 2020 (March 14, 2020): 1–15. http://dx.doi.org/10.1155/2020/4915638.
Повний текст джерелаАнотація:
In this paper, we investigate the performance of the non-orthogonal multiple access (NOMA) system with incremental relaying, where the relay is employed with amplify-and-forward (AF) or decode-and-forward (DF) protocols. To characterize the outage behaviors of the incremental cooperative NOMA (ICN) system, new closed-form expressions of both exact and asymptotic outage probability for two users are derived. In addition, the performance of the conventional cooperative NOMA (CCN) system is analyzed as a benchmark for the the purpose of comparison. We confirm that the outage performance of the distant user is enhanced when ICN system is employed. Numerical results are presented to demonstrate that (1) the near user of the ICN system achieves better outage behavior than that of the CCN system in the low signal-to-noise ratio (SNR) region; (2) the outage performance of distant user for the DF-based ICN system is superior to that of the AF-based ICN system when the system works in cooperative NOMA transmission mode; and (3) in the low SNR, the throughput of the ICN system is higher than that of the CCN system.
8
Ezzine, Sana, Fatma Abdelkefi, Jean Pierre Cances, Vahid Meghdadi, and Ammar Bouallégue. "Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission." Wireless Communications and Mobile Computing 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/4827274.
Повний текст джерелаАнотація:
Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC) channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC) system, in which Orthogonal Frequency Division Multiplexing (OFDM) is used, is considered in this paper. We derive and compare the PLC channel capacity and the end-to-end Average BER (ABER) for OFDM-based direct link (DL) BB-PLC system and for OFDM-based two-hop relaying BB-PLC system for Amplify and Forward (AF) and Decode and Forward (DF) protocols. We analyze the improvements when we consider the direct link in a cooperative communication when the relay node only transmits the correctly decoded signal. Maximum ratio combining is employed at the destination node to detect the transmitted signal. In addition, in this paper, we highlight the impact of the relay location on the channel capacity and ABER for AF and DF transmission protocols. Moreover, an efficient use of the direct link was also investigated in this paper.
9
Lee, Sangku, Janghyuk Youn, and Bang Chul Jung. "Hybrid AF/DF Cooperative Relaying Technique with Phase Steering for Industrial IoT Networks." Energies 14, no. 4 (February 10, 2021): 937. http://dx.doi.org/10.3390/en14040937.
Повний текст джерелаАнотація:
For the next generation of manufacturing, the industrial internet of things (IoT) has been considered as a key technology that enables smart factories, in which sensors transfer measured data, actuators are controlled, and systems are connected wirelessly. In particular, the wireless sensor network (WSN) needs to operate with low cost, low power (energy), and narrow spectrum, which are the most technical challenges for industrial IoT networks. In general, a relay-assisted communication network has been known to overcome scarce energy problems, and a spectrum-sharing technique has been considered as a promising technique for the radio spectrum shortage problem. In this paper, we propose a phase steering based hybrid cooperative relaying (PSHCR) technique for the generic relay-assisted spectrum-shared WSN, which consists of a secondary transmitter, multiple secondary relays (SRs), a secondary access point, and multiple primary access points. Basically, SRs in the proposed PSHCR technique operate with decode-and-forward (DF) relaying protocol, but it does not abandon the SRs that failed in decoding at the first hop. Instead, the SRs operate with amplify-and-forward (AF) protocol when they failed in decoding at the first hop. Furthermore, the SRs (regardless of operating with AF or DF protocol) that satisfy interference constraints to the primary network are allowed to transmit a signal to the secondary access point at the second hop. Note that phase distortion is compensated through phase steering operation at each relay node before second-hop transmission, and thus all relay nodes can operate in a fully distributed manner. Finally, we validate that the proposed PSHCR technique significantly outperforms the existing best single relay selection (BSR) technique and cooperative phase steering (CPS) technique in terms of outage performance via extensive computer simulations.
10
Khodakhah, Farnaz, Aamir Mahmood, Patrik Österberg, and Mikael Gidlund. "Multiple Access-Enabled Relaying with Piece-Wise and Forward NOMA: Rate Optimization under Reliability Constraints." Sensors 21, no. 14 (July 13, 2021): 4783. http://dx.doi.org/10.3390/s21144783.
Повний текст джерелаАнотація:
The increasing proliferation of Internet-of-things (IoT) networks in a given space requires exploring various communication solutions (e.g., cooperative relaying, non-orthogonal multiple access, spectrum sharing) jointly to increase the performance of coexisting IoT systems. However, the design complexity of such a system increases, especially under the constraints of performance targets. In this respect, this paper studies multiple-access enabled relaying by a lower-priority secondary system, which cooperatively relays the incoming information to the primary users and simultaneously transmits its own data. We consider that the direct link between the primary transmitter–receiver pair uses orthogonal multiple access in the first phase. In the second phase, a secondary transmitter adopts a relaying strategy to support the direct link while it uses non-orthogonal multiple access (NOMA) to serve the secondary receiver. As a relaying scheme, we propose a piece-wise and forward (PF) relay protocol, which, depending on the absolute value of the received primary signal, acts similar to decode-and-forward (DF) and amplify-and-forward (AF) schemes in high and low signal-to-noise ratio (SNR), respectively. By doing so, PF achieves the best of these two relaying protocols using the adaptive threshold according to the transmitter-relay channel condition. Under PF-NOMA, first, we find the achievable rate region for primary and secondary receivers, and then we formulate an optimization problem to derive the optimal PF-NOMA time and power fraction that maximize the secondary rate subject to reliability constraints on both the primary and the secondary links. Our simulation results and analysis show that the PF-NOMA outperforms DF-NOMA and AF-NOMA-based relaying techniques in terms of achievable rate regions and rate-guaranteed relay locations.
11
Wang, Dawei, Pinyi Ren, Qinghe Du, Li Sun, and Yichen Wang. "Downlink and Uplink Cooperative Transmission for Primary Secrecy Based Cognitive Radio Sensor Networks." International Journal of Distributed Sensor Networks 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/152851.
Повний текст джерелаАнотація:
Aiming at allocating more licensed spectrum to wireless sensor nodes (SNs) under the constraint of the information security requirement of the primary system, in this paper, we propose a cooperative relaying and jamming secure transmission (CRJS) scheme in which SNs will relay primary message and jam primary eavesdrop concurrently with SN’s downlink and uplink information transmission in cognitive radio sensor networks (CRSNs). In our proposed CRJS scheme, SNs take advantages of physical layer secure technologies to protect the primary transmission and acquire some interference-free licensed spectrum as a reward. In addition, both decode-and-forward (DF) and amplify-and-forward (AF) relaying protocols are investigated in our proposed CRJS scheme. Our object is to maximize the transmission rate of SNs by optimal allocating of the relaying power, jamming power, and downlink and uplink transmit power under the target secure transmission rate requirement of the primary system. Moreover, two suboptimal algorithms are proposed to deal with these optimization problems. Furthermore, we analyze the transmission rate of SNs and allocate the relaying power, jamming power, and downlink and uplink transmit power for the asymptotic scenarios. Simulation results demonstrate the performance superiority of our developed strategy over conventional jamming scheme in terms of the transmission rate of WSN.
12
Tweneboah-Koduah, Samuel, Emmanuel Ampoma Affum, Kwame Agyemang-Prempeh Prempeh Agyekum, Sunday Adeola Ajagbe, and Matthew O. Adigun. "Performance of Cooperative Relay NOMA with Large Antenna Transmitters." Electronics 11, no. 21 (October 26, 2022): 3482. http://dx.doi.org/10.3390/electronics11213482.
Повний текст джерелаАнотація:
The potential of the Non-Orthogonal Multiple Access (NOMA) approach for wireless communications in the fifth generation (5G) and beyond can not be underestimated. This is because users with favorable channel conditions can serve as relays to improve system performance by employing Successive Interference Cancellation (SIC). Lately, the combination of NOMA and the cooperative relay has attracted the interest of researchers. The analysis of cooperative relay NOMA (CR-NOMA) with a massive multiple-input multiple-output (mMIMO) system is mainly based on theoretical channel models such as the correlated-based stochastic channel model (CBSM) even though the geometric-based stochastic channel model (GBSM) has been found to provide better, practical and realistic channel properties. This, in our view, is due to computational challenges. Again, the performance of CR-NOMA systems using the GBSM channel model with large antenna transmitters and network coding schemes has attracted little attention in academia. Therefore, the need to study mMIMO CR-NOMA that considers channel properties such as path-loss, delay profile and tilt angle has become vital. Furthermore, the co-existing of large antenna transmitters with coding schemes needs further investigation. In this paper, we study the performance of a two-stage mMIMO CR-NOMA network where the transmitter is represented as a uniform rectangular array (URA) or cylindrical array (CA). The communication channel from the transmitter (TX) to the user equipment (UE) through a relay station (RS) is modeled with a 3GPP’s three-dimensional (3D) GBSM mMIMO channel model. To improve the analytical tractability of 3D GBSM, we defined the antenna element location vectors using the physical dimension of the antenna array and incorporated them into the 3D channel model. Bit-error rates, achievable rates and outage probabilities (OP) are examined using amplify-and-forward (AF) and decode-and-forward (DF) coding schemes. Results obtained show with fixed power allocation and SNR of 20 dB, far or weak users can attain a high achievable rate using DF and URA. Again, from the results, the combination of AF and CA presents better outage probabilities. Finally, the results indicate that the performance difference between CBSM and GBSM is marginal, even though the proposed 3D GBSM channel model has a higher degree of random parameters and computational complexities.
13
Boujemâa, Hatem. "Static hybrid amplify and forward (AF) and decode and forward (DF) relaying for cooperative systems." Physical Communication 4, no. 3 (September 2011): 196–205. http://dx.doi.org/10.1016/j.phycom.2011.05.001.
Повний текст джерела
14
Van, Hoang Thien, Quyet-Nguyen Van, Danh Hong Le, Hoang-Phuong Van, Jakub Jalowiczor, Hoang-Sy Nguyen, and Miroslav Voznak. "Opportunistic DF-AF Selection Relaying in Hybrid Wireless and Power Line Communication for Indoor IoT Networks." Sensors 21, no. 16 (August 13, 2021): 5469. http://dx.doi.org/10.3390/s21165469.
Повний текст джерелаАнотація:
This manuscript investigates the system performance of hybrid wireless and power line communication networks for indoor Internet of Things applications. Differentiating itself from the existing literature, the performance of the direct link and dual-hop energy harvesting relay-aided links is analyzed under the condition of indoor fading modeled by log-normal distribution. Moreover, the manuscript presents the analytical expressions of the successful transmission probability of the deployed opportunistic decode-and-forward and amplify-and-forward relay selection scheme, and validates them with Monte Carlo simulations. Moreover, the impact of different system parameters on the successful transmission probability is revealed. For the considered hybrid system, in general, the opportunistic decode-and-forward relaying scheme outperforms the opportunistic amplify-and-forward relaying scheme. As importantly, increasing the source to relay distance and power splitting ratio over certain limits significantly deteriorates the system performance, indicated by the decrease in the successful transmission probability.
15
Tran, Thanh-Nam, and Miroslav Voznak. "HD/FD and DF/AF with Fixed-Gain or Variable-Gain Protocol Switching Mechanism over Cooperative NOMA for Green-Wireless Networks." Sensors 19, no. 8 (April 18, 2019): 1845. http://dx.doi.org/10.3390/s19081845.
Повний текст джерелаАнотація:
This article studied the application of multiple protocol switching mechanism (PSM) over cooperating Non-Orthogonal Multiple Access (NOMA) networks to minimize the probability of outage and maximize the system throughput and energy efficiency (EE). This study investigated six scenarios: (1) a cooperative NOMA system with half-duplex (HD) and decode-and-forward (DF) protocols at the relay; (2) a cooperative NOMA system with full-duplex (FD) and DF protocols at the relay; (3) a cooperative NOMA system with HD and amplification amplify-and-forward (AF) with fixed-gain (FG) protocols at the relay; (4) a cooperative NOMA system with HD and amplification AF with variable-gain (VG) protocols at the relay; (5) a cooperative NOMA system with FD and amplification AF with FG protocols at the relay; (6) a cooperative NOMA system with FD and amplification AF with VG protocols at the relay. Based on the results of analysis and simulations, the study determined the transmission scenario for best system performance. This paper also proposed a mechanism to switch between HD/FD and DF/AF with FG/VG protocols in order to improve the quality of service (QoS) for users with a weak conditional channel. This mechanism can be deployed in future 5G wireless network sensors. Finally, EE was also assessed in relation to future green-wireless networks (G-WNs).
16
Rizinski, Maryan, and Venceslav Kafedziski. "Ergodic Rates of the Fast Rayleigh Fading Relay Channel for Different Cooperative Strategies." Serdica Journal of Computing 7, no. 2 (December 13, 2013): 101–14. http://dx.doi.org/10.55630/sjc.2013.7.101-114.
Повний текст джерелаАнотація:
This paper investigates the ergodic rates of three cooperative strategies for the fast Rayleigh fading relay channel, namely, decode-and forward (DF), compress-and-forward (CF) and amplify-and-forward (AF). The transmitter-relay, relay-receiver and transmitter-receiver links experience independent fast Rayleigh fading. Our analysis considers both fullduplex and half-duplex modes of operation of the relay channel, assuming that perfect transmit channel distribution information (CDI) is available at the transmitter and the relay. The ergodic rates are compared under different channel conditions to the corresponding upper capacity bounds of the relay channel and to the rate of direct transmission in order to investigate when it is beneficial to use a certain cooperative strategy. Cooperative transmission makes the ergodic rates approach or even become identical to theupper capacity bounds if some conditions are satisfied. The results show that DF and CF outperform AF as they are more complex strategies, while AF itself achieves higher rates than direct transmission in most channel scenarios, thus trading performance for implementation simplicity.ACM Computing Classification System (1998): E.4, C.2.1.
17
Han, Chun Lei, Mei Lu Lin, and Ye Yang. "Performance Analysis for Hybrid Cooperative Beamforming in Wireless Relay Networks." Applied Mechanics and Materials 543-547 (March 2014): 3435–40. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.3435.
Повний текст джерелаАнотація:
This paper considers a relay-assisted hybrid cooperative beamforming system in independent and identically Rayleigh fading channels. In this system, each relay can adaptively employ amplify-and-forward (AF) or decode-and-forward (DF) protocol for maximizing the instantaneous signal-to-noise ratio (SNR). Tight upper and lower bounds for the outage probability have been derived in closed form, based on which we investigate the achievable diversity of the hybrid cooperative beamforming system. We also present the corresponding upper and lower bounds of the average channel capacity. Numerical results are provided to validate our theoretic analyses.
18
Ojo, Festus K., Bidemi Olajide, Damilare O. Akande, and Olasunkanmi F. Oseni. "Performance Evaluation of a Wireless Cooperative Network with Maximal Ratio Combining Technique." FUOYE Journal of Engineering and Technology 7, no. 2 (June 30, 2022): 169–73. http://dx.doi.org/10.46792/fuoyejet.v7i2.792.
Повний текст джерелаАнотація:
Research on wireless communication is on the rise due to its capability in improving communication in terms of spectrum efficiency, power and communication reliability. In wireless network, power is consumed mostly in the process of data transmission, hence, the need for cooperative relay protocol and technique to improve systems’ performance through power management and quality of service (QoS). Although, there are various cooperative protocols which include: amplify-and-forward, decode-and-forward among others. However, by using these cooperative protocols, the amount of power consumed and QoS still require improvement. Thus, in this work the quest for incorporation of Maximal Ratio Combining (MRC) technique with the Decode-and-Forward (DF) relay protocol in cooperative network. The cooperative network with DF protocol considered consists of the source, destination and relay(s) nodes. The MRC was incorporated at the destination just to combine the received signals from the relay nodes. Moreover, the system’s simulation was carried out by using MATLAB R2020a and evaluated using bit error rate and power consumption as the performance metrics. The obtained results showed that the QoS and power consumption of the considered cooperative network was considerably improved when MRC was employed in the network in comparison with an existing work.
19
Prof. Dr. Noorullah Shariff, Ms Tejashri H. Mohite,. "Evaluation and Analysis for Maximum Lifespan of Wireless Sensor Networks by Energy-Efficient Design." International Journal on Recent and Innovation Trends in Computing and Communication 9, no. 4 (April 30, 2021): 01–05. http://dx.doi.org/10.17762/ijritcc.v9i4.5470.
Повний текст джерелаАнотація:
Wireless Sensor Networks (WSNs) have used worldwide in the past few years and are now being used in health monitoring ,disaster management, defense, telecommunications, etc. Such networks are used in many industrial and consumer applications such as industrial process and environment monitoring, among others. A WSN network is a collection of specialized transducers known as sensor nodes with a communication link distributed randomly in any locations to monitor environmental parameters such as water level, and temperature. Each sensor node is equipped with a transducer, a signal processor, a power unit, and a transceiver. WSNs are now being widely used to monitor environmental parameters, including the amount of gas, water, temperature, humidity, oxygen level, dust, etc. The WSN for environment monitoring can be equivalently replaced by a multiple-input multiple-output (MIMO) relay network. Multi-hop relay networks have attracted significant research interest in recent years for their capability in increasing the coverage range. The network communication link from a source to a destination is implemented using the amplify-and-forward (AF) or decode-and-forward (DF) schemes. The AF relay receives information from the previous relay and simply amplifies the received signal and then forwards it to the next relay. On the other hand, the DF relay first decodes the received signal and then forwards it to the next relay in the second stage if it can perfectly decode the incoming signal. For analytical simplicity, in this thesis, we consider the AF relaying scheme and the results of this work can also be developed for the DF relay.
20
Sarma, Subhra Sankha, Ranjay Hazra, and Peter Han Joo Chong. "Performance Analysis of DF Relay-Assisted D2D Communication in a 5G mmWave Network." Future Internet 14, no. 4 (March 24, 2022): 101. http://dx.doi.org/10.3390/fi14040101.
Повний текст джерелаАнотація:
Enabling D2D communication in the mmWave band has many obstacles that must be mitigated. The primary concern is the introduction of interference from various sources. Thus, we focused our work on the performance of decode-and-forward (DF) relay-assisted D2D communication in the mmWave band to increase the coverage probability and energy efficiency (EE). Three modes are proposed for D2D communication to prevail. The bitwise binary XOR operation was executed at the relay node, which increased the security feature. The radius of coverage was derived, which indicated the switching of the modes. The diffused incoherent scattering power was also considered as part of the power consumption. Furthermore, a unique relay selection scheme, the dynamic relay selection (DRS) method, is proposed to select the optimal relay for information exchange. A comparison of the proposed DF relay scheme with the amplify-and-forward (AF) scheme was also made. Finally, the simulation results proved the efficacy of the proposed work.
21
Sinouvassane, Arunmozhi, and Nagarajan G. "Performance Of Full-Duplex One-Way And Two-Way Cooperative Relaying Networks." Indonesian Journal of Electrical Engineering and Computer Science 9, no. 2 (February 1, 2018): 526. http://dx.doi.org/10.11591/ijeecs.v9.i2.pp526-538.
Повний текст джерелаАнотація:
<p>The wireless research requires concurrent transmission and reception in a single time/frequency channel with good spectral efficiency. The Full duplex system is the alternate for the conventional half duplex systems. An investigation on the need for a full duplex two way (FD-TWR) and one way relaying (FD-OWR) to improve the performance of outage probability and average rate employing amplify-and-forward (AF) and decode-and-forward (DF) protocol is considered. Further the relaying systems performance under the network coding schemes is taken into consideration. The outage probability and average rate of FD-TWR and FD-OWR using a physical layer network coding was performed. In contrast to “straightforward” network coding which performs arithmetic function on digital bit streams after information have been received. The result shows the DF protocol achieves better outage probability and average rate, when compared to the AF protocol. And comparing the full duplex schemes like FD-TWR and FD-OWR, it is found that the FD-TWR achieves better outage probability and average rate, when compared to the FD-OWR. The performance was extended with different loop interference among the relay antennas. The performance show that FD-TWR performs well even in spite of loop interference.<em></em></p><p><em> </em></p>
22
Cao, Ning, Yuchang Ye, and Minghe Mao. "The Effect of Misdetection Probability on the Performance of Cooperative-Relaying-Based Cognitive Radio Systems." Mobile Information Systems 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/1051632.
Повний текст джерелаАнотація:
Cognitive radio (CR) is a promising solution to address the more and more congested radio spectrum. Cooperative relaying can provide a better transmission performance for the secondary user (SU), while the performance of the primary user (PU, also named licensed user) should be preferentially protected especially when there is misdetection probability. In this paper, in order to keep the PU away from outage caused by the interference from the SU under a certain signal-to-noise ratio (SNR), the maximum SNR for the SU can be derived by using the rate decaying factor (RDF). Then, based on the maximum channel gain and the maximum SNR, the outage probability is analyzed using decode-and-forward (DF) relaying and amplify-and-forward (AF) relaying schemes. Numerical results show that the outage probability decreases when the power allocation factor increases for DF strategy, while the outage probability has error floor when the power allocation factor increases for AF strategy. And the relaying scheme based on the maximum channel gain outperforms that based on the maximum SNR when the power allocation factor and detection probability are small, while the relaying scheme based on the maximum SNR outperforms that based on the maximum channel gain when the power allocation factor is large. What is more, AF relaying has better outage performance in the practical implementation.
23
Zhang, Xiaokai, Bangning Zhang, Kang An, Zhuyun Chen, and Daoxing Guo. "Auction-Based Secondary Relay Selection on Overlay Spectrum Sharing in Hybrid Satellite–Terrestrial Sensor Networks." Sensors 19, no. 22 (November 19, 2019): 5039. http://dx.doi.org/10.3390/s19225039.
Повний текст джерелаАнотація:
In this paper, we investigate the auction-based secondary relay selection on overlay spectrum sharing in hybrid satellite–terrestrial sensor networks (HSTSNs), where both the decode-and-forward (DF) and amplify-and-forward (AF) relay protocols are analyzed based on time division multiple access (TDMA). As both the primary and secondary networks are rational, honest but with incomplete network information, they prefer to obtain maximum possibility payoffs by the cooperation between the primary and secondary networks, and the competition among secondary networks. Hence, Vickery auction is introduced to achieve the effective and efficient secondary relay selection by distinct sub-time slot allocation for one shot in terms of a distributed manner. Finally, numerical simulations are provided to validate the effectiveness of the auction mechanism on cooperative spectrum sharing in HSTSNs for secondary relay selection. Besides, the effect of key factors on the performance of the auction mechanism are analyzed in details.
24
Wang, Zih-Sin, Liang-Hung Lin, Jyh-Horng Wen, Yen-Ju Lin, and Chien-Erh Weng. "Performance Analysis of AF Cooperative Relaying Networks with SWIPT." Electronics 11, no. 4 (February 15, 2022): 589. http://dx.doi.org/10.3390/electronics11040589.
Повний текст джерелаАнотація:
Cooperative communication networks have received more attention due to its ability to improve the signal quality of terminal devices by spatial diversity. Under recent advance in internet of things, In order to extend the service life of terminal devices powered by battery, simultaneous wireless information and power transfer (SWIPT) technique has been emphasize. The terminal devices can harvest energy and decode information from the same radio frequency (RF) signal using by SWIPT technique. In this paper, we combine both techniques to study the performance of both conventional cooperative relaying networks without SWIPT and cooperative relaying networks with SWIPT under an amplify-and-forward (AF) relaying network. To the best of our knowledge, no one simultaneously studies and compares the performance of both systems. Therefore, the outage probabilities of both systems are carried out, and numerical results are compared in this paper. The main results include: (1) Compared with conventional cooperative communication, the cooperative communication with SWIPT has better outage probability only when the distance between relay node and source node is less than one. It implies that, to outperform the conventional cooperative communication, the relay node should harvest enough energy for signal transmission. (2) With the diversity of direct path and relay path, the outage probability of cooperative communication with EH under an AF relaying network has been significantly reduced.
25
Nguyen, Ba Cao, Xuan Hung Le, Van Duan Nguyen, and Le The Dung. "On the Capacity of Full-Duplex AF/DF Relay System with Energy Harvesting for Vehicle-to-Vehicle Communications." Wireless Communications and Mobile Computing 2021 (January 7, 2021): 1–11. http://dx.doi.org/10.1155/2021/8865615.
Повний текст джерелаАнотація:
This paper studies the ergodic capacity (EC) of full-duplex (FD) amplify-and-forward (AF) and decode-and-forward (DF) relay system with energy harvesting (EH) for vehicle-to-vehicle (V2V) communications. Unlike previous works on FD-EH systems, we consider the case that both relay and destination are mobile vehicles while the source is a static base station. We mathematically derive the exact closed-form expressions of ECs of both AF and DF protocols of the considered FD-EH-V2V relay system over cascade (double) Rayleigh fading. Our numerical results show that the ECs in the case of the V2V communication system are reduced compared to those in the case of stationary nodes. Also, with a specific value of residual self-interference (RSI), the ECs of the considered FD-EH-V2V relay system can be higher or lower than those of half-duplex- (HD-) EH-V2V system, depending on the average transmission power of the source. Furthermore, when the transmission power of the source and RSI are fixed, the ECs of the considered system can achieve peak values by using optimal EH time duration. On the other hand, the ECs of both AF and DF protocols reach the capacity floors in the high signal-to-noise ratio (SNR) regime due to the RSI impact. Also, the effect of RSI dominates the impact of cascade Rayleigh fading in the high SNR regime. Finally, we validate our analysis approach through Monte-Carlo simulations.
26
Li, Jie, Jianrong Bao, Shenji Luan, Bin Jiang, and Chao Liu. "Power Optimized Single Relay Selection with an Improved Link-Adaptive-Regenerative Protocol." Journal of Electrical and Computer Engineering 2018 (July 2, 2018): 1–8. http://dx.doi.org/10.1155/2018/8364594.
Повний текст джерелаАнотація:
To improve the reliability and efficiency in cooperative communications, a power optimized single relay selection scheme is proposed by increasing the diversity effort with an improved link-adaptive-regenerative (ILAR) protocol. The protocol determines the forwarding power of a relay node by comparing the signal-to-noise ratio (SNR) at both sides of the node; thus it improves the power efficiency. Moreover, it also proposes a single relay selection strategy to maximize the instantaneous SNR product, which ensures the approximate best channel link quality for good relay forwarding. And the system adjusts the forwarding power in real time and also selects the best relay node participated in the cooperative forwarding. In addition, the cooperation in the protocol is analyzed and the approximate expression of the bit-error-rate (BER) and the outage probability at high SNRs are also derived. Simulation results indicate that the BER and outage probability of the relay selection scheme by the ILAR protocol outperform other contrast schemes of current existing protocols. At BER of 10−2, the proposed scheme with ILAR protocol outperforms those of the decoded-and-forward (DF), the selected DF (SDF), and the amplify-and-forward (AF) protocols by 3.5, 3.5 and 7 dB, respectively. Moreover, the outage probability of the relay system decreases with the growth of the relay number. Therefore, the proposed relay selection scheme with ILAR strategies can be properly used in cooperative communications for good reliability and high power efficiency.
27
Wang, Hui, Jian Dong, Kun Tang, and Heyuan Shi. "Outage Performance Analysis of NOMA in Wireless Powered Cognitive Radio Networks with AF and DF Relaying Techniques." Entropy 23, no. 11 (November 5, 2021): 1463. http://dx.doi.org/10.3390/e23111463.
Повний текст джерелаАнотація:
Improving spectral efficiency under a certain energy limitation is an important design metric for future wireless communications as a response to the growing transmission demand of wireless devices. In order to improve spectral efficiency for communication systems without increasing energy consumption, this paper considers a non-orthogonal multiple access (NOMA)–based cognitive radio network, with the assistance of a wireless-powered relay station (RS), and then analyzes the system outage performance under amplified-and-forward (AF) and decoded-and-forward (DF) cooperative transmission modes. Specifically, the base station (BS) has the opportunity to cooperate by transmitting information through the RS, depending on whether the RS can harvest sufficient RF energy for cooperative transmission. That is to say, when the energy stored by the RS is sufficient for cooperative transmission, the RS will assist the BS to forward information; otherwise, the BS will send information through direct links, while the RS converts the radio frequency (RF) signals sent by the BS into energy for future transmission. Moreover, the transmission power required by the RS for cooperative transmission is usually relatively large, while the amount of harvested energy by the RS in a transmission slot is usually low, so it takes several consecutive time slots to accumulate enough transmission energy. To this end, we utilize a discrete-time Markov chain to describe the processes of charging and discharging of the RS. Subsequently, we derive the closed-form outage probabilities of both the primary and secondary systems for the considered system in AF and DF modes through mathematical analysis, and verify the accuracy of the analyses through Monte Carlo simulation. The simulation results show that the two proposed cooperative transmission schemes with AF and DF relaying techniques outperform both direct transmission and other similar schemes in both the primary and secondary system, while the DF scheme can provide better performance than the AF scheme within the range of setting values.
28
Abrar, Muhammad, Xiang Gui, and Amal Punchihewa. "Low Complexity Joint Sub-Carrier Pairing, Allocation and Relay Selection in Cooperative Wireless Networks." International Journal of Communication Networks and Information Security (IJCNIS) 6, no. 3 (April 17, 2022). http://dx.doi.org/10.17762/ijcnis.v6i3.608.
Повний текст джерелаАнотація:
Multi-carrier cooperative relay-based wireless communication is of particular interest in future wireless networks. In this paper we present resource allocation algorithm in which sub-carrier pairing is of particular interest along with fairness constraint in multi-user networks. An optimization of sub-carrier pair selection is formulated through capacity maximization problem. Sub-carrier pairing is applied in both two-hop Amplify & Forward (AF) and Decode & Forward (DF) cooperative multi-user networks. We develop a less complex centralized scheme for joint Sub-carrier pairing and allocation along with relay selection. The computational complexity of the proposed algorithms has been analyzed and performance is compared with Exhaustive Search Algorithm.
29
Akande, Damilare O., Festus K. Ojo, Samson I. Ojo, Sunday A. Olayanju, and Idowu A. Ojerinde. "Lifetime Enhancement of Cooperative Wireless Ad-Hoc Networks using Optimal Power Allocation and Relay Selection Scheme." FUOYE Journal of Engineering and Technology 7, no. 3 (August 17, 2022). http://dx.doi.org/10.46792/fuoyejet.v7i3.872.
Повний текст джерелаАнотація:
Cooperative Communication (CC) has greatly reduced the effect of multipath fading, thereby improving the quality of transmitted signals in wireless ad-hoc networks. However, existing works on CC suffers from degradation of network lifetime due to inaccurate selection of the optimal relay terminal. This results in frequent battery recharging due to high energy consumed and battery depletion. Hence, in this paper, lifetime enhancement of cooperative wireless ad-hoc networks is carried out using allocated optimal power and relay selection scheme to ensure an optimal selection of the best relay by balancing and conserving the energy consumption of the nodes. Transmit power optimization problems were formulated for Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying strategies to obtain the optimal power allocations required to transmit the information. The proposed scheme named Energy-Aware Relay Selection (EARS) was simulated in MATLAB software environment and average network lifetime performance evaluation was performed. The result obtained shows that the proposed EARS improves the network performance by 10.06% and 3.56% for AF and DF relaying strategies, respectively over the existing power-aware relay selection schemes.
30
Guo, Weidong, and Yuxi Liu. "On the performance of physical layer security in virtual full-duplex non-orthogonal multiple access system." EURASIP Journal on Wireless Communications and Networking 2021, no. 1 (June 12, 2021). http://dx.doi.org/10.1186/s13638-021-02009-y.
Повний текст джерелаАнотація:
AbstractThis paper investigates physical layer security analysis of cooperative non-orthogonal multiple access (NOMA) communication system. A virtual full-duplex (VFD) relaying scheme with an untrusted amplify-and-forward (AF) half-duplex (HD) relay and a trusted decode-and-forward (DF) HD relay is used in this system to improve the spectral efficiency. In order to prevent the untrusted relay from eavesdropping, a simple and practical cooperative jamming scheme is designed to confuse the untrusted relay. The exact expressions of effective secrecy throughput (EST) for NOMA users and approximate expression of EST for non-NOMA user are derived. All theoretical results are validated by numerical simulations which demonstrate that the proposed VFD-NOMA scheme is superior to existing HD-NOMA scheme in cooperative system and jamming plays an important role for obtaining acceptable EST. In addition, simulation results shows that the best secrecy performance highly depends on the system parameters such as transmit powers and jamming signal power.
31
Umar, Syed, Tariku Birhanu Yadesa, Kamal Mohammed Jimalo, and M. Paul N. Vijaya Kumar. "Interpretation of AF-DF protocols for FitureMulti Layer-IDMA." International Journal of Scientific Research in Science, Engineering and Technology, June 3, 2020, 332–37. http://dx.doi.org/10.32628/ijsrset207367.
Повний текст джерелаАнотація:
In this article, we investigate the bit error rate (BER) performance in a cooperative relay communication system for multilateral IDMA (ML-IDMA) using the maximum ratio combination (MRC) technique. ). ). We investigate the effect of the number of lines on performance and find the average error rate in bits of the AF relay scheme (Amplify and Forward) using the signal-to-noise ratio (SNR) of the relay connection in closed form. The proposed system for evaluating ML-IDMA performance is provided with a different number of layers and a different number of relays in an ML-IDMA cooperative environment. The simulation results show that the BER performance of a 4-relay IDMA double layer system (K = 2) is approximately 4 dB. In addition, the bandwidth saving is 50%. Ultimately, BER performance deteriorates as the number of layers increases and the proposed system increases bandwidth by approximately 1/K.
32
BRAGANC, MANISHA CRASTO, HASANALI G. VIRANI, and SHAILESH KHANOLKAR. "PERFORMANCE EVALUATION OF RELAYING SCHEMES FOR WIRELESS COMMUNICATION SYSTEMS." International Journal of Smart Sensor and Adhoc Network., January 2013, 157–61. http://dx.doi.org/10.47893/ijssan.2013.1155.
Повний текст джерелаАнотація:
The evaluation of MIMO (multiple-input multiple-output) Relay wireless system is carried out and compared against the performance of a SISO (single-input single-output) Relay wireless system. The encoding scheme used in MIMO is Alamouti coding and decoding is done by the Maximum Likelihood (ML) detector. A comparison is made between the SISO non-regenerative amplify-and-forward (AF) and regenerative decode-and-forward (DF) relaying schemes. The plots of bit error rate (BER) versus signal to noise ratio (SNR) are simulated by incorporating Rayleigh fading condition in the presence of additive white Gaussian noise(AWGN) using MATLAB.
33
Pandya, Sharnil, Patteti Krishna, Ravi Shankar, and Ankur Singh Bist. "Examination of the fifth-generation vehicular simultaneous wireless information and power transfer cooperative non-orthogonal multiple access network in military scenarios considering time-varying and imperfect channel state information conditions." Journal of Defense Modeling and Simulation: Applications, Methodology, Technology, August 10, 2021, 154851292110330. http://dx.doi.org/10.1177/15485129211033040.
Повний текст джерелаАнотація:
In a defense scenario, the communicating nodes are mobile and, due to this, the fading channel links become time selective in nature. Non-orthogonal multiple access (NOMA) is a promising technique in modern wireless communication systems, and it is employed in a variety of defense ad hoc wireless communication scenarios where nodes are mobile and it is difficult to estimate the channel coefficients perfectly. NOMA contributes to increased spectral efficiency (SE), firstly by enabling fifth-generation new radio deployment in the 3.5 GHz frequency range, and secondly by employing a simultaneous wireless information and power transfer (SWIPT) time switching and power splitting-based cooperative NOMA (C-NOMA) network where simple radio frequency circuitry is used for energy harvesting. NOMA together with the selective decode-and-forward (S-DF) protocol will increase the SE and energy efficiency simultaneously. The outage probability performance is evaluated for various values of the fading severity parameter and node velocity forming the channel error. It is significant to note that digital S-DF-based SWIPT C-NOMA performs much better than an analog amplify-and-forward-based C-NOMA SWIPT system.