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Journal articles on the topic 'HARQ'

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Author: Grafiati

Published: 4 June 2021

Last updated: 1 June 2024

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1

WANG, Yumei, Jiawei LIANG, Hao WANG, Eiji OKI, and Lin ZHANG. "ePec-LDPC HARQ: An LDPC HARQ Scheme with Targeted Retransmission." IEICE Transactions on Communications E99.B, no. 10 (2016): 2168–78. http://dx.doi.org/10.1587/transcom.2016ebp3004.

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2

Yu, Wei, Fusheng Zhu, Jun Wu, Rui Wang, Haoqi Ren, and Zhifeng Zhang. "HARQ-Chaotic: Analog Chaotic Code Applied in HARQ Scheme of Wireless Communication System." Wireless Communications and Mobile Computing 2019 (April 24, 2019): 1–13. http://dx.doi.org/10.1155/2019/3728127.

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This paper proposes a novel symbol-level combining hybrid automatic repeat request (HARQ) scheme based on analog chaotic code and named HARQ-Chaotic. The transmitter of HARQ-Chaotic adopts analog chaotic code to encode Quadrature Amplitude Modulation (QAM) symbols of retransmission packets to combat fading and noise. As the analog chaotic code can only handle sources with amplitudes in the range of [-0.5, 0.5], QAM symbols must be scaled into this range. We derived the optimal scaling factor through theoretical analysis. A joint algorithm combining with novel soft chaotic decoder and novel soft QAM demapper is proposed for the receiver to enhance the performance of the whole communication system. We implemented HARQ-Chaotic with LDPC codes and 16-QAM/64-QAM to carry out simulations in both AWGN channels and multipath fading channels. Massive simulation results demonstrate that the proposed HARQ-Chaotic has 1dB-4dB gain over traditional HARQ-Chase combining (HARQ-CC) scheme in block error rate (BLER) performance.

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3

Rykova, Tatiana, Barış Göktepe, Thomas Schierl, Konstantin Samouylov, and Cornelius Hellge. "Analytical Model and Feedback Predictor Optimization for Combined Early-HARQ and HARQ." Mathematics 9, no. 17 (August 31, 2021): 2104. http://dx.doi.org/10.3390/math9172104.

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In order to fulfill the stringent Ultra-Reliable Low Latency Communication (URLLC) requirements towards Fifth Generation (5G) mobile networks, early-Hybrid Automatic Repeat reQuest (e-HARQ) schemes have been introduced, aimed at providing faster feedback and thus earlier retransmission. The performance of e-HARQ prediction strongly depends on the classification mechanism, data length, threshold value. In this paper, we propose an analytical model that incorporates e-HARQ and Hybrid Automatic Repeat reQuest (HARQ) functionalities in terms of two phases in discrete time. The model implies a fast and accurate way to get the main performance measures, and apply optimization analysis to find the optimal values used in predictor’s classification. We employ realistic data for transition probabilities obtained by means of 5G link-level simulations and conduct extensive experimental analysis. The results show that at false positive probability of 10−1, the e-HARQ prediction with the found optimal parameters can achieve around 20% of gain over HARQ at False Negative (FN) of 10−1 and around 7.5% at FN of 10−3 in terms of a mean spending time before successful delivery.

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4

Sakr, H. A., and M. A. Mohamed. "Performance Evaluation Using Smart: HARQ Versus HARQ Mechanisms Beyond 5G Networks." Wireless Personal Communications 109, no. 3 (June 10, 2019): 1503–28. http://dx.doi.org/10.1007/s11277-019-06624-3.

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5

Bian, Hongxiu, and Rongke Liu. "Reliable and Energy-Efficient LEO Satellite Communication with IR-HARQ via Power Allocation." Sensors 22, no. 8 (April 15, 2022): 3035. http://dx.doi.org/10.3390/s22083035.

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This paper examines reliable and energy-efficient transmission in low earth orbit (LEO) satellite communication systems. In particular, we analyze the link transmission characteristics of the LEO satellite to the ground user and model the channel as a combination of large-scale fading and small-scale fading. Based on this, we consider an incremental redundancy hybrid automatic repeat request (IR-HARQ) technique with a variable-power allocation method, and we call it the IR-HARQ-VPA scheme. In this method, the outage probability after each IR-HARQ round can be obtained through numerical integration based on the fast Fourier transform (NI-FFT). This method is suitable for any number of HARQ transmission rounds and can improve the accuracy compared with previous approximation methods. In addition, variable-power allocation based on the genetic algorithm (VPA-GA) is introduced to reduce the energy consumption. The simulation results show that the proposed IR-HARQ-VPA scheme cannot only meet the requirements of transmission reliability but also achieves higher energy efficiency than IR-HARQ with equal power (IR-HARQ-EP) transmission and a previously proposed variable-power allocation method. Moreover, the simulation results in a LEO satellite communication window also confirm the effectiveness of the proposed IR-HARQ-VPA scheme.

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6

Wu, Yue, Kuanlin Mu, Kaiyu Duan, Shishu Yin, and Hongwen Yang. "On the Secure Performance of Intelligent Reflecting Surface-Assisted HARQ Systems." Entropy 25, no. 3 (March 17, 2023): 519. http://dx.doi.org/10.3390/e25030519.

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This paper analyzes the physical layer security performance of hybrid automatic repeat request (HARQ) systems with the assistance of an intelligent reflecting surface (IRS) and aims to reveal the primary factors that enhance PLS. First, closed-form expressions for the connection outage probability (COP) and secrecy outage probability (SOP) in HARQ with chase combining (HARQ-CC) are acquired using the generalized-K (KG) distribution. Then, these two critical metrics are derived while adopting HARQ with incremental redundancy (HARQ-IR), resorting to the mixture gamma (MG) distribution and the Mellin transform. Diversity and coding gain are also addressed through an asymptotic analysis of the COP and SOP. Finally, an evaluation of the numerical results demonstrates that a greater gain in the main channel and the wiretap channel can be produced by increasing the number of meta-surfaces rather than increasing the maximum transmission number, except for the higher signal-to-noise (SNR) region of HARQ-IR where the latter is preferred. This finding provides a significant guidance for the joint configuration of IRS and HARQ to achieve secure communication.

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7

Jabi, Mohammed, Abdellatif Benyouss, Mael Le Treust, Etienne Pierre-Doray, and Leszek Szczecinski. "Adaptive Cross-Packet HARQ." IEEE Transactions on Communications 65, no. 5 (May 2017): 2022–35. http://dx.doi.org/10.1109/tcomm.2017.2661758.

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8

Xu, Kui, Wenfeng Ma, Lei Zhu, Youyun Xu, Yuanyuan Gao, Dongmei Zhang, and Wei Xie. "NTC-HARQ: Network–Turbo-Coding Based HARQ Protocol for Wireless Broadcasting System." IEEE Transactions on Vehicular Technology 64, no. 10 (October 2015): 4633–44. http://dx.doi.org/10.1109/tvt.2014.2374235.

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9

Shi, Xiaoye, Haiting Zhu, Fei Ding, Zhaowei Zhang, and Nan Bao. "Tradeoff-HARQ Scheme for Full-Duplex SWIPT DF Relay." Wireless Communications and Mobile Computing 2021 (October 25, 2021): 1–7. http://dx.doi.org/10.1155/2021/5550825.

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The SWIPT (simultaneous wireless information and power transfer) DF (decoding and forwarding) relay system could achieve the purpose of both increasing revenue and reducing expenditure. By analysing the system model and transmission characteristics of full-duplex relay, this paper optimizes the retransmission slot structure to enhance the system performance. Firstly, the state transition model is established based on the analysis of the retransmission slot structure. Secondly, the state probability of each state and the transition probability between states are calculated to obtain the total data passing rate, energy transmission efficiency, and total transmission time. Thirdly, in order to compare the performance of various HARQ (hybrid automatic repeat request) schemes more effectively, JNTP (joint normalized throughput of information transmission and energy transmission) is constructed. Monte Carlo simulations finally confirm that the proposed tradeoff-HARQ scheme outperforms the regular-HARQ scheme in terms of JNTP: the performance of the tradeoff-HARQ scheme is 0.03883 higher than that of the regular-HARQ scheme when the total power limit is 20 dB and 0.00651 higher than that of the regular-HARQ scheme when the total power limit is 30 dB.

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10

Zheng, Ya Dan, Jian Bo Li, Yong Luo, Ming Ke Dong, and Jian Jun Wu. "Forced-Retransmission Based Hybrid HARQ Scheme for GEO Satellite Communications." Advanced Materials Research 846-847 (November 2013): 651–54. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.651.

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In this paper, a hybrid HARQ scheme was proposed by combing forced retransmission and traditional HARQ together, after analyzing the characteristics of satellite channel and the problem encountered when utilizing HARQ scheme in GEO satellite communication system. The forced retransmission can make a packet be correctly decoded more quickly and shorten the waiting delay. Meanwhile, to balance the delay and throughput, the proper parameters were given for the proposed hybrid scheme. Simulation results show that the proposed scheme performs well at decreasing the waiting delay, especially when SNR is low. The conclusion can be drawn that the proposed scheme can improve the HARQ performance in GEO satellite communication systems.

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11

Sun, Peng, Jing Yang, Ya Jie Chen, and Chun Zhou. "The Realization of Receiving and Reporting the HARQ-ACK Information in LTE System." Advanced Materials Research 989-994 (July 2014): 4132–35. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.4132.

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A brief introduction of hybrid automatic repeat request (HARQ) is given first, and then a description of physical uplink shared channel (PUCCH) or physical uplink shared channel (PUSCH) receiving and reporting the HARQ-ACK information in bundling mode or multiplexing mode is made in detail. Based on the principle, a scheme is designed to solve the problem of receiving and reporting the HARQ-ACK information.

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12

Kundaeli, Herald N. "The analysis of truncated ARQ and HARQ schemes using transition diagrams." International Journal of Engineering, Science and Technology 12, no. 2 (June 1, 2020): 35–51. http://dx.doi.org/10.4314/ijest.v12i2.5.

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In digital communication systems, ARQ and HARQ schemes are employed in order to ensure efficient transmission of information and utilisation of the channel by retransmitting information that has not being received correctly at the receiver. In some applications, however, such as real-time services, the quality of information is degraded if too many retransmission trials are employed for each unit of erroneously received information. The retransmissions are therefore limited leading to truncated ARQ and HARQ schemes. In this study we develop a new method for deriving the expressions for the throughput efficiencies of truncated ARQ and HARQ schemes and investigate how the efficiencies vary with the number of allowed retransmissions. Keywords: ARQ, HARQ, Throughput Efficiency, Truncated ARQ.

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13

Tseng, Hsien Wei, Yih Guang Jan, Wei Chen Lee, Shih Nan Lu, Yang Han Lee, and Ming Hsueh Chuang. "HARQ Performance Analysis in IEEE 802.16m System." Applied Mechanics and Materials 284-287 (January 2013): 2756–60. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.2756.

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In this paper we simulate and analyze the system performance of implementing two Hybrid Automatic Retransmission Request (HARQ) architectures for IEEE 802.16m system, one is a modified Type I HARQ architecture with adaptive modulation and coding (AMC) scheme and the other is the Chase Combining. In the simulation, the buffer size of HARQ has been set to certain limit and under the condition of having the packet error ratio (PER) limited by 10% then the selection of proper HARQ structure with suitable AMC scheme for IEEE 802.16m system has been proposed for mobile speeds at 3 km/hr, 80 km/hr or 350 km/hr and with a distance of 300m between the mobile station and its serving base station.

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14

SONG, Bin, Hao QIN, Mingming YANG, and Lifeng GU. "Selective Retransmission Method for HARQ." IEICE Transactions on Communications E94-B, no. 3 (2011): 796–97. http://dx.doi.org/10.1587/transcom.e94.b.796.

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15

Jabi, Mohammed, Mustapha Benjillali, Leszek Szczecinski, and Fabrice Labeau. "Energy Efficiency of Adaptive HARQ." IEEE Transactions on Communications 64, no. 2 (February 2016): 818–31. http://dx.doi.org/10.1109/tcomm.2015.2506698.

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16

Hosseini, Seyyed Saleh, Jamshid Abouei, and Murat Uysal. "Fast-Decodable MIMO HARQ Systems." IEEE Transactions on Wireless Communications 14, no. 5 (May 2015): 2827–40. http://dx.doi.org/10.1109/twc.2015.2395411.

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17

Khosravirad, Saeed R., Leszek Szczecinski, and Fabrice Labeau. "Rate Adaptation for Cooperative HARQ." IEEE Transactions on Communications 62, no. 5 (May 2014): 1469–79. http://dx.doi.org/10.1109/tcomm.2014.031614.130685.

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18

Guan, Mengsheng, Min Zhu, and Baoming Bai. "Windowed Joint Detection and Decoding with IR-HARQ for Asynchronous SCMA Systems." Entropy 25, no. 6 (June 13, 2023): 930. http://dx.doi.org/10.3390/e25060930.

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To improve the decoding performance of asynchronous sparse code multiple access (SCMA) systems over additive white Gaussian noise (AWGN) channels, this paper proposes a novel windowed joint detection and decoding algorithm for a rate-compatible (RC), LDPC code-based, incremental redundancy (IR) hybrid automatic repeat quest (HARQ) scheme. Since incremental decoding can exchange information iteratively with the detections made at previous consecutive time units, we propose a windowed joint detection and decoding algorithm. The extrinsic information exchanging process is performed between the decoders and the previous w detectors at different consecutive time units. Simulation results show that the sliding-window IR-HARQ scheme for the SCMA system outperforms the original IR-HARQ scheme with a joint detection and decoding algorithm. The throughput of the SCMA system with the proposed IR-HARQ scheme is also improved.

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19

Et Tolba, Mohamed, Samir Saoudi, Raphaël Visoz, and Tarik Ait-Idir. "Chip-Level HARQ Chase Combining for HSUPA." Research Letters in Communications 2009 (2009): 1–4. http://dx.doi.org/10.1155/2009/230276.

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Hybrid automatic repeat request (HARQ) is used in high-speed uplink packet access (HSUPA) to increase the data rate. Chase combining is the simplest of HARQ algorithms. It provides a time diversity and requires a small memory. In this paper, we propose a technique to increase the chase combining efficiency. In this method, HARQ transmissions are seen as additional receive antennas which are jointly combined at chip-level using a space-time linear minimum square error (LMMSE). We demonstrate that the chase combining diversity gain is considerably increased especially for high-order modulation.

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20

Nadeem, Faisal, Mahyar Shirvanimoghaddam, Yonghui Li, and Branka Vucetic. "Delay-Sensitive NOMA-HARQ for Short Packet Communications." Entropy 23, no. 7 (July 9, 2021): 880. http://dx.doi.org/10.3390/e23070880.

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This paper investigates the two-user uplink non-orthogonal multiple access (NOMA) paired with the hybrid automatic repeat request (HARQ) in the finite blocklength regime, where the target latency of each user is the priority. To limit the packet delivery delay and avoid packet queuing of the users, we propose a novel NOMA-HARQ approach where the retransmission of each packet is served non-orthogonally with the new packet in the same time slot. We use a Markov model (MM) to analyze the dynamics of the uplink NOMA-HARQ with one retransmission and characterize the packet error rate (PER), throughput, and latency performance of each user. We also present numerical optimizations to find the optimal power ratios of each user. Numerical results show that the proposed scheme significantly outperforms the standard NOMA-HARQ in terms of packet delivery delay at the target PER.

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21

Park, Sangjoon. "Kalman Filter Based Turbo Equalizer for MIMO-HARQ Systems." Journal of Korean Institute of Communications and Information Sciences 47, no. 4 (April 30, 2022): 599–602. http://dx.doi.org/10.7840/kics.2022.47.4.599.

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22

Park, Sangjoon, and Sooyong Choi. "MMSE Based Continuous Turbo Equalizer for MIMO-HARQ Systems." Journal of Korea Information and Communications Society 39A, no. 10 (October 31, 2014): 619–21. http://dx.doi.org/10.7840/kics.2014.39a.10.619.

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23

Shakir, Shaffath Hussain, and A. Rajesh. "Improved calendar disc scheduler for LTE advanced networks with HARQ." Journal of High Speed Networks 27, no. 2 (July 7, 2021): 139–49. http://dx.doi.org/10.3233/jhs-210656.

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Long Term Evolution Advanced (LTE-A) is a broadband wireless technology that supports variety of services with different data rate. In order to achieve this the evolved Node B (eNB) uses different features provided in the 3GPP standards. Features like Carrier Aggregation (CA), Multiple input and Multiple output (MIMO) and Hybrid Automatic Repeat Request (HARQ) help to increase the throughput and spectral efficiency. In this paper, a novel two-level calendar disc algorithm with HARQ is introduced at the eNB for effectively scheduling real time and non-real time traffic with different service types. The algorithm also uses a burst profile management module that analyzes the current user profile and notifies the scheduler about the need to change in profile based on power boosting. The Calendar Disc Scheduler (CDS) is improved by adding HARQ retransmission index as a parameter in calculating the metric weight. The scheduler was tested for both adaptive and non-adaptive methods of HARQ in both synchronous and asynchronous modes. The proposed improved CDS scheduler was simulated with LTESim simulator and compared with calendar disc algorithm without HARQ improvements. Results show that the proposed scheduling method provides increased performance in terms of goodput, delay and spectral efficiency.

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24

Hakimi, Walid, and Ammar Mahmoud. "Performance Evaluation of Space-Time and Harq Diversity in MIMO HSDPA." International Journal of Mobile Computing and Multimedia Communications 4, no. 3 (July 2012): 71–86. http://dx.doi.org/10.4018/jmcmc.2012070105.

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Multi-antenna techniques can be used to achieve improved system performance, including improved system capacity (more users per cell) and improved coverage (possibility for larger cells), as well as improved service provisioning, for example, higher per-user data rates. This study provides an overview of space-time diversity technique using Alamouti codes applied to the 3G evolution. The delays introduced by HARQ retransmission decrease the performance of the HSDPA system. Multi-antenna techniques are specifically applied to HSDPA to avoid HARQ retransmissions. The authors demonstrate that space-time Rake detector in MIMO 2x2 based on Alamouti code without HARQ process could give better performances than MIMO 2x1 taking into account the HARQ context. In the case of MIMO 2x2,they also observed that the limit of retransmissions affects the system performance and efficiency. Using the generalized Alamouti coding technique in MIMO 4x4 with Multipath Parallel Interference Canceller (MPIC) detector, we achieve notable improvement of performance under the same channel and signal to-Noise Ratio (SNR) conditions.

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25

Vangelista, Lorenzo, and Marco Centenaro. "Performance Evaluation of HARQ Schemes for the Internet of Things." Computers 7, no. 4 (September 25, 2018): 48. http://dx.doi.org/10.3390/computers7040048.

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Hybrid Automatic Repeat reQuest (HARQ) techniques are widely employed in the most important wireless systems, e.g., the Long Term Evolution (LTE) cellular standard, to increase the reliability of the communication. Despite these schemes have been widely studied in literature in the past several years, the recent results obtained by Polyanskiy, Poor, and Verdú on the finite-blocklength regime disclosed new possibilities for the research on HARQ schemes. Indeed, new communications trends, which are usually part of the Internet of Things (IoT) paradigm, are characterized by very short packet sizes and a high reliability requirement and, therefore, they call for efficient HARQ techniques. In many scenarios, the energy efficiency of the communication plays a key role as well. In this paper, we aim at providing a comprehensive performance comparison of various kinds of HARQ schemes in the context of short-packet transmissions with energy constraints. We derive optimal power allocation strategies and we show that a minimum 50% energy saving can be achieved after very few transmission attempts if we enable packet combining at the receiver side.

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26

Khreis, Alaa, Francesca Bassi, Philippe Ciblat, and Pierre Duhamel. "Multi-Layer HARQ With Delayed Feedback." IEEE Transactions on Wireless Communications 19, no. 9 (September 2020): 6224–37. http://dx.doi.org/10.1109/twc.2020.3001420.

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27

Wu, Wenhao, Hans Mittelmann, and Zhi Ding. "Modulation Design for MIMO-CoMP HARQ." IEEE Communications Letters 21, no. 2 (February 2017): 290–93. http://dx.doi.org/10.1109/lcomm.2016.2618796.

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28

Sassioui, Redouane, Mohammed Jabi, Leszek Szczecinski, Long Bao Le, Mustapha Benjillali, and Benoit Pelletier. "HARQ and AMC: Friends or Foes?" IEEE Transactions on Communications 65, no. 2 (February 2017): 635–50. http://dx.doi.org/10.1109/tcomm.2016.2619716.

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29

Choi, Jinho. "On Channel-Aware Secure HARQ-IR." IEEE Transactions on Information Forensics and Security 12, no. 2 (February 2017): 351–62. http://dx.doi.org/10.1109/tifs.2016.2613846.

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30

Makki, Behrooz, Alexandre Graell i Amat, and Thomas Eriksson. "HARQ Feedback in Spectrum Sharing Networks." IEEE Communications Letters 16, no. 9 (September 2012): 1337–40. http://dx.doi.org/10.1109/lcomm.2012.070512.112003.

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31

TAKEDA, K., H. TOMEBA, K. TAKEDA, and F. ADACHI. "DS-CDMA HARQ with Overlap FDE." IEICE Transactions on Communications E90-B, no. 11 (November 1, 2007): 3189–96. http://dx.doi.org/10.1093/ietcom/e90-b.11.3189.

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32

Le Treust, Mael, Leszek Szczecinski, and Fabrice Labeau. "Rate Adaptation for Secure HARQ Protocols." IEEE Transactions on Information Forensics and Security 13, no. 12 (December 2018): 2981–94. http://dx.doi.org/10.1109/tifs.2018.2833799.

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33

Chiao-Yin Huang, Wen-Ching Chung, Chung-Ju Chang, and Fang-Ching Ren. "An Intelligent HARQ Scheme for HSDPA." IEEE Transactions on Vehicular Technology 60, no. 4 (May 2011): 1602–11. http://dx.doi.org/10.1109/tvt.2011.2125809.

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34

Zhu, Hai, Dan Wang, and Peng Sun. "A Scheme of Downlink HARQ Scheduling in TDD LTE-A." International Journal of Information and Communication Sciences 1, no. 3 (December 30, 2016): 43–46. http://dx.doi.org/10.11648/j.ijics.20160103.12.

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In order to provide a higher peak data rate, carrier aggregation (CA) is implemented into Long Term Evolution Advanced (LTE-A) systems. However, more and more downlink hybrid automatic repeat request (HARQ) feedback information need to be transmitted. Especially, in time division duplexing (TDD) systems must comply with the updownconfig, the complexity and storage of HARQ scheduling increase largely under CA. In this paper, a HARQ scheduling scheme is proposed which is based on dynamic information tables to generate and schedule the downlink feedback information of acknowledgment/negative acknowledgment (ACK/NACK) in Long Term Evolution Advanced (LTE-A) system. Some storing tables based on component carriers are designed and a dynamic updated scheme is proposed, which reduces the scheduling complexity and memory occupation effectively.

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35

Gacanin, Haris, and Fumiyuki Adachi. "Throughput of Type II HARQ-OFDM/TDM Using MMSE-FDE in a Multipath Channel." Research Letters in Communications 2009 (2009): 1–4. http://dx.doi.org/10.1155/2009/695620.

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In type II hybrid ARQ (HARQ) schemes, the uncoded information bits are transmitted first, while the error correction parity bits are sent upon request. Consequently, frequency diversity cannot be exploited during the first transmission. In this paper, we present the use of OFDM/TDM with MMSE-FDE and type II HARQ to increase throughput of OFDM due to frequency diversity gain.

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36

Rykova, Tatyana V. "Construction and analysis of a transmission model in 5G cell in the form of two-phase queuing system with account of the retransmission prediction mechanism." T-Comm 16, no. 6 (2022): 19–24. http://dx.doi.org/10.36724/2072-8735-2022-16-6-19-24.

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The mechanism of early channel adaptation based on e-HARQ (early Hybrid Automatic Repeat reQuest) prediction for the downlink of a mobile network, which solves the problem of improving information transmission characteristics, is studied. The model is a two-phase queuing system (QS). In the QS, at the first phase, the prediction process with the possibility of relaying is modeled, and at the second phase, the process of message processing by the user terminal based on the HARQ physical layer protocol is considered. The HARQ protocol in the 5G network provides the transmitter with an acknowledgment message ACK in case of successful decoding of the packet, and NACK in case of error. Its main disadvantage is the limitation on RTT (Round Trip Time) - the time interval between the initial and retransmission processes. Numerical analysis of the obtained probabilistic-temporal characteristics (PTCR) is carried out. At the first stage, the transition probabilities were found by modeling the link layer of the 5G network. Obtaining realistic values for the transition probabilities allows using this analytical model to analyze and optimize existing e-HARQ prediction schemes. Next, a simulation complex was developed to check the correctness of the analytical model.

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37

Lin, Shih-Yang, Miao-Hui Yang, and Shuo Jia. "An Adaptive Hybrid Automatic Repeat Request (A-HARQ) Scheme Based on Reinforcement Learning." Electronics 12, no. 19 (October 3, 2023): 4127. http://dx.doi.org/10.3390/electronics12194127.

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V2X communication is susceptible to attenuation and fading caused by external interference. This interference often leads to bit error and poor quality and stability of the wireless link, and it can easily disrupt packet transmission. In order to enhance communication reliability, the 3rd Generation Partnership Project (3GPP) introduced the Hybrid Automatic Repeat Request (HARQ) technology for both 4G and 5G systems. Nevertheless, it can be improved for poor communication conditions (e.g., heavy traffic flow, long-distance transmission), especially in advanced or cooperative driving scenarios. In this paper, we propose an Adaptive Hybrid Automatic Repeat Request (A-HARQ) scheme that can reduce the average block error rate, the average number of retransmissions, and the round-trip time (RTT). It adapts the Q-learning model to select the timing and frequency of retransmission to enhance the transmission reliability. We also design some transmission schemes—K-repetition, T-delay and [T, K]-overlap—which are used to shorten latency and avoid packet collision. Compared with the conventional 5G HARQ, our simulation results show that the proposed A-HARQ scheme decreases the system’s average BLER, the number of retransmissions, and the RTT to 5.55%, 1.55 ms, and 0.97 ms, respectively.

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38

Kim, Dong Ho, and Ye Hoon Lee. "Incremental Redundancy Hybrid ARQ (IR-HARQ) Scheme Using Block LDPC Codes." Journal of Korea Information and Communications Society 38A, no. 8 (August 30, 2013): 662–68. http://dx.doi.org/10.7840/kics.2013.38a.8.662.

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39

Wang, Dan, Peng Sun, Fang Tao Li, and Ling Yun Zhou. "The Realization of HARQ Based on UE in the Uplink of LTE System." Applied Mechanics and Materials 513-517 (February 2014): 2008–11. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.2008.

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First, the basic principle of HARQ is introduced in detail. From the UE perspective, a general method based on table look-up of uplink HARQ implementation is proposed. Then the implementation principle is described through four detailed examples procedure. This method ensures the accuracy of the data transmission in timing aspect and improve the stability of the system, and it is verified in the RF conformance test platform.

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R Shankar, Arathi, Raghavendra G, and V. Sambasiva Rao. "HARQ Implementation for Efficient MAC to MAC Video Streaming over Mobile WiMAX." INTERNATIONAL JOURNAL OF MANAGEMENT & INFORMATION TECHNOLOGY 5, no. 1 (August 15, 2013): 455–69. http://dx.doi.org/10.24297/ijmit.v5i1.4489.

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IEEE 802.16e is the standard for Mobile WiMAX which was introduced by the IEEE committee to provide broadband access in rural and urban areas over fixed wireless channels. Mobile WiMAX is an enhanced version of IEEE 802.16 standard with mobility support. There are lots of challenges involved in the service provided by the Mobile WiMAX. Efficient data transfer between different layers of mobile WiMAX is one of the major research issues. In this work HARQ (Hybrid Automatic Repeat Request) technique is implemented in Qualnet environment for an efficient transmission of video streaming across PHY(Physical) and MAC(Medium Access Control) layer of mobile WiMAX (Worldwide Interoperability for Microwave Access). HARQ utilizes both FEC (Forward Error Correction) an d ARQ (Automatic Repeat Request) techniques to reduce the delay, jitter and to increase throughput efficiently under prescribed quality of service constraint. Different Scheduling schemes and cross layer approaches that support mobile WiMAX are analysed. mmSIR scheduler is used in this work since it allocates resources priority wise. Diffferent network quality parameters like end to end delay,average jitter,and average throughput have been analysed by using existing ARQ and implemented HARQ techniques.Both ARQ and HARQ techniques are compared for a video application.

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Park, Sangjoon. "Selective Symbol-Level Combining Scheme for LDPC Coded MIMO-HARQ Systems." Journal of Korean Institute of Communications and Information Sciences 45, no. 4 (April 30, 2020): 682–85. http://dx.doi.org/10.7840/kics.2020.45.4.682.

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Kapsis, Theodore T., and Athanasios D. Panagopoulos. "Power Allocation for Reliable and Energy-Efficient Optical LEO-to-Ground Downlinks with Hybrid ARQ Schemes." Photonics 9, no. 2 (February 4, 2022): 92. http://dx.doi.org/10.3390/photonics9020092.

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Satellites in low earth orbit (LEO) are currently being deployed for numerous communication, positioning, space and Earth-imaging missions. To provide higher data rates in direct-to-user links and earth observation downlinks, the free-space optics technology can be employed for LEO-to-ground downlinks. Moreover, the hybrid automatic repeat request (HARQ) can be adopted since the propagation latency is low for LEO satellites. In this work, a power allocation methodology is proposed for optical LEO-to-ground downlinks under weak turbulence employing HARQ retransmission schemes. Specifically, the average power consumption is minimized given a maximum transmitted power constraint and a target outage probability threshold to ensure energy efficiency and reliability, respectively. The optimization problem is formulated as a constrained nonlinear programming problem and solved for Type I HARQ, chase combining (CC) and incremental redundancy (IR) schemes. The solutions are derived numerically via iterative algorithms, namely interior-point (IP) and sequential quadratic programming (SQP), and validated through an exhaustive (brute-force) search. The numerical simulations provide insight into the performance of the retransmission schemes regarding average power. More specifically, Type I HARQ has the worst output, CC has a moderate one, and IR exhibits the best performance. Finally, the IP algorithm is a slower but more accurate solver, and SQP is faster but slightly less accurate.

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Kunal, Kaustuv, R. C. Tripathi, and Vrijendra Singh. "An HARQ Based Optimized Error Correction Technique." International Journal of Computer Applications 9, no. 1 (September 10, 2010): 1–5. http://dx.doi.org/10.5120/1353-1826.

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Pan, Gaofeng, Jia Ye, Yu Tian, and Mohamed-Slim Alouini. "On HARQ Schemes in Satellite-Terrestrial Transmissions." IEEE Transactions on Wireless Communications 19, no. 12 (December 2020): 7998–8010. http://dx.doi.org/10.1109/twc.2020.3018501.

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Mheich, Zeina, Mael Le Treust, Florence Alberge, and Pierre Duhamel. "Rate Adaptation for Incremental Redundancy Secure HARQ." IEEE Transactions on Communications 64, no. 2 (February 2016): 765–77. http://dx.doi.org/10.1109/tcomm.2015.2514284.

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Choi, Jinho. "On HARQ-IR for Downlink NOMA Systems." IEEE Transactions on Communications 64, no. 8 (August 2016): 3576–84. http://dx.doi.org/10.1109/tcomm.2016.2585651.

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Muhammad, Zia, Hasan Mahmood, Awais Ahmed, and Nazar Abbas Saqib. "Selective HARQ Transceiver Design for OFDM System." IEEE Communications Letters 17, no. 12 (December 2013): 2229–32. http://dx.doi.org/10.1109/lcomm.2013.101613.131869.

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Pfletschinger, Stephan, David Declercq, and Monica Navarro. "Adaptive HARQ With Non-Binary Repetition Coding." IEEE Transactions on Wireless Communications 13, no. 8 (August 2014): 4193–204. http://dx.doi.org/10.1109/twc.2014.2314457.

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Cao, Y., J. Gu, L. Qi, and D. Yang. "Degree distribution based HARQ for irregular LDPC." Electronics Letters 42, no. 6 (2006): 363. http://dx.doi.org/10.1049/el:20063676.

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Lee, Wonju, Osvaldo Simeone, Joonhyuk Kang, Sundeep Rangan, and Petar Popovski. "HARQ Buffer Management: An Information-Theoretic View." IEEE Transactions on Communications 63, no. 11 (November 2015): 4539–50. http://dx.doi.org/10.1109/tcomm.2015.2472015.

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