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Comparison of hybrid ARQ packet combining algorithm in high speed downlink packet access in a multipath fading channel

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2002年第7期E85A卷 1557-1568页

作者： Miki, N Atarashi, H Abeta, S Sawahashi, M NTT DoCoMo Inc Wireless Labs Yokosuka Kanagawa 2398536 Japan

This paper presents a comparison of the throughput performance employing hybrid automatic repeat request (HARQ) with packet combining, such as Type-I with packet combining (simply Chase combining hereafter) and Type-II (Incremental redundancy hereafter), using turbo coding in a multipath fading channel in high speed downlink packet access (HSDPA). We apply a, multipath interference canceller (TOPIC) to remove the influence of severe multipath interference. Link level simulation results show that the maximum throughput using Incremental redundancy with 64QAM is improved by approximately 5-8% compared to that using Chase combining, and that the required average received signal energy of 12 code channels per chip-to-background noise spectrum density (E-c/N-0) at the throughput of 4 Mbps with Incremental redundancy is decreased by approximately 1.0 dB rather than that with Chase combining when the vehicular speed is higher than approximately 30 km/h. Furthermore, we elucidate based on the system level simulation that although no improvement is obtained in a slow mobility environment such as the average vehicular speed of 3 km/h, the achieved throughput of Incremental redundancy is increased by approximately 5-6% and 13% for the average vehicular speed of 30 km/h and 120 km/h, respectively;compared to that with Chase combining.

关键词： hybrid ARQ adaptive modulation and coding multipath interference canceller high speed downlink packet access

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Link adaptation for wireless systems

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WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2014年第16期14卷 1509-1521页

作者： Tran, Sang V. Eltawil, Ahmed M. Univ Calif Irvine Irvine CA 92697 USA

To improve the robustness and reliability of wireless transmissions, two complementary link adaptation techniques are employed: adaptive modulation and coding (AMC) at the physical layer and hybrid automatic retransmission request (HARQ) at the medium access control layer. Because of their effectiveness in combating errors induced by the wireless channel, AMC and HARQ are now integral components of most emerging broadband wireless system standards, for example, LTE and WiMAX. Spectral efficiency (SE) as measured in bit per second per Hertz is one important parameter used to characterize a wireless system for comparison between different systems or between different configurations of the same system. This work provides a holistic approach of cross-layer optimizations with the intent of maximizing SE by combining AMC and HARQ. It formulates closed-form equations for calculating the average SE for wireless systems with the Rayleigh fading channel model. A new online algorithm is developed to optimize SE for both Rayleigh and non-Rayleigh fading channel. Simulations using proven LTE model are performed to compare SE obtained from closed-form equations and the developed algorithm for different system configurations. With the developed algorithm to determine how many retransmissions required in addition to the initial transmission in advance depending on the current wireless channel condition, the latency can be reduced up to 24ms when sending the initial transmission and all of its retransmissions sooner than waiting for retransmission requests as is done previously. Copyright (c) 2012 John Wiley & Sons, Ltd.

关键词： wireless LTE link adaptation adaptive modulation and coding automatic repeat request cross-layer optimizations

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Probabilistically Coded modulation Formats for 5G Mobile Fronthaul Networks

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2019年第16期37卷 3882-3892页

作者： Yang, Mingwei Rastegarfar, Houman Djordjevic, Ivan B. Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA Univ Arizona Coll Opt Sci Tucson AZ 85721 USA

The centralized/cloud radio access network architecture is being considered as a promising solution for fifth-generation cellular networks. In particular, the stringent capacity and latency requirements of the fronthaul segment call for innovations in the design of new architectures and transceivers that support adaptive communication resource allocation between centralized baseband processing units and remote radio heads. In this paper, we propose probabilistically coded three-level pulse amplitude modulation and five-point quadrature amplitude modulation schemes in hybrid mobile fronthaul (MFH) networks that support both coherent detection and direct detection. We propose encoding and decoding algorithms and optimize the decoder configuration through simulations. Based on a distributed pseudorandom encoding technique developed in our earlier work, we adapt the modulation type and code rate per fronthaul connection in real-time. Using two separate software-defined networking enabled downlink and uplink transmission testbeds employing code division multiplexing technology, we demonstrate the benefits of our proposed modulation formats for multicast transmission in hybrid networking scenarios as well as the advantages of adaptive bidirectional transmission in MFH networks.

关键词： adaptive modulation and coding coherent detection (CD) direct detection (DD) mobile fronthaul (MFH) pulse amplitude modulation (PAM) quadrature amplitude modulation (QAM) software-defined networking (SDN) wavelength routing

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A Highly Efficient DAMA Algorithm for Making Maximum Use of both Satellite Transponder Bandwidth and Transmission Power

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IEICE TRANSACTIONS ON COMMUNICATIONS 2012年第8期E95B卷 2619-2630页

作者： Nakahira, Katsuya Sugiyama, Takatoshi Nishiyama, Hiroki Kato, Nei NTT Corp NTT Access Network Serv Syst Labs Yokosuka Kanagawa 2390847 Japan Tohoku Univ Grad Sch Informat Sci Sendai Miyagi 9808579 Japan

This paper proposes a novel satellite channel allocation algorithm for a demand assigned multiple access (DAMA) controller. In satellite communication systems, the channels' total bandwidth and total power are limited by the satellite's transponder bandwidth and transmission power (satellite resources). Our algorithm is based on multi-carrier transmission and adaptive modulation methods. It optimizes channel elements such as the number of sub-carriers, modulation level, and forward error correction (FEC) coding rate. As a result, the satellite's transponder bandwidth and transmission power can be simultaneously used to the maximum and the overall system capacity, i.e., total transmission bit rate, will increase. Simulation results show that our algorithm increases the overall system capacity by 1.3 times compared with the conventional fixed modulation algorithm.

关键词： satellite communication channel allocation adaptive modulation and coding multi-carrier transmission DAMA

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A novel scalable video broadcasting method over MIMO-OFDM systems

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2015年第11期69卷 1672-1682页

作者： Li, Shuying Harbin Inst Technol Sch Elect & Informat Engn Harbin 150001 Peoples R China

A hybrid decoding scheme for the scalable video codec (SVC) coded video wireless broadcasting system is proposed. The SVC coded video layers are grouped into various groups and each group is encoded independently into a signal layer, which are then transmitted from allocated antennas over certain time-frequency blocks. Each receiver employs the successive group decoder to decode the signal streams of interest by treating other signal streams as interference. The transmitter performs adaptive coding and modulation, and transmission antenna and subcarrier allocation, based on the rate feedback from the receivers. The proposed hybrid receiver switches to the minimum mean square error (MMSE) decoder if the rate can be achieved by the MMSE decoding. Extensive simulations are provided to demonstrate the performance gain of the proposed SVC broadcasting scheme over the conventional MMSE decoding and the successive interference cancelation algorithm. (c) 2015 Elsevier GmbH. All rights reserved.

关键词： Scalable video coding MIMO-OFDM Optimal successive group decoder LDPC adaptive modulation and coding

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Modeling and Classifying Error-Correcting Codes With Soft Decision-Based HMMs for Intelligent Wireless Communication

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IEEE TRANSACTIONS ON COGNITIVE COMMUNICATIONS AND NETWORKING 2023年第2期9卷 293-303页

作者： Li, Sida Zhang, Yimeng Huang, Zhiping Zhou, Jing Zhao, Yongjie Natl Univ Def Technol Coll Intelligent Sci Changsha 410070 Peoples R China

The classification of error correcting code (ECC) types is an important task for intelligent wireless communication. Previous solutions to this problem usually ignored the time sequences feature and considered the incoming data as separate code words. In this paper, a novel framework for code type classification is proposed based on the Hidden Markov Model (HMM). The structural differences of different types of ECCs are modeled and analyzed using the transition probability and the emission probability. An HMM-based classifier is proposed to recognize the types of ECCs from the intercepting bitstream. To improve the performance in the noisy transmission environment, the basic classifier is enhanced by soft decision message and relative posterior probability. Simulation results show that the proposed scheme outperforms other existing methods in erroneous conditions and the classification accuracy is associated with the sequence length and decision approach.

关键词： Hidden Markov models Codes Error correction codes Estimation Markov processes Wireless communication Convolutional codes adaptive modulation and coding blind semi-blind recognition error correcting codes machine learning

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Multi-parameter performance analysis for decentralized cognitive radio networks

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WIRELESS NETWORKS 2014年第4期20卷 787-803页

作者： Xenakis, Dionysis Passas, Nikos Merakos, Lazaros Univ Athens Dept Informat & Telecommun Athens 15784 Greece

In this paper, we investigate the impact of primary user activity, secondary user activity, interface switching, channel fading and finite-length queuing on the performance of decentralized cognitive radio networks. The individual processes of these service-disruptive effects are modeled as Markov chains based on cross-layer information locally available at the network nodes. A queuing analysis is conducted and various performance measures are derived regarding the packet loss, throughput, spectral efficiency, and packet delay distribution. Numerical results demonstrate the impact of various system parameters on the system performance, providing insights for cross-layer design and autonomous decision making in decentralized cognitive radio networks.

关键词： Cognitive radio Decentralized networks User activity Interface switching Channel fading adaptive modulation and coding Performance analysis

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Dynamic resource allocation in adaptive wireless OFDMA systems

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WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2012年第11期12卷 985-998页

作者： Xenakis, Dionysis Tsolkas, Dimitris Passas, Nikos Alonistioti, Nancy Merakos, Lazaros Univ Athens Dept Informat & Telecommun Athens 15784 Greece

Modern wireless orthogonal frequency division multiple access (OFDMA) systems incorporate dynamic resource allocation (DRA), adaptive modulation and coding (AMC), and power control (PC) to exploit multiuser diversity and achieve higher system throughput. In the literature, only a few proposed algorithms deal with the contiguous DRA problem according to which a contiguous collection of resources can be allocated to each user. This paper formulates this high complexity problem, provides a suitable decision metric and a simple yet efficient solution. The proposed algorithm allocates in each step a contiguous collection of resources to the pending user that leads to the highest estimated correctly received number of bits. Simulation results show that, in this way, considerably improved performance can be achieved in terms of overall system throughput, spectral efficiency, and served traffic. Copyright (c) 2010 John Wiley & Sons, Ltd.

关键词： OFDMA dynamic resource allocation adaptive modulation and coding power control adjacent subcarrier permutation

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Impact of Atmospheric Parameters on the Propagated Signal Power of Millimeter-Wave Bands Based on Real Measurement Data

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IEEE ACCESS 2019年 7卷 113626-113641页

作者： Han, Congzheng Duan, Shu Chinese Acad Sci Inst Atmospher Phys Key Lab Middle Atmosphere & Global Environm Obser Beijing 100029 Peoples R China Univ Chinese Acad Sci Coll Earth & Planetary Sci Beijing 100049 Peoples R China Chengdu Univ Informat Engn Sch Elect Engn Chengdu 610225 Sichuan Peoples R China Jiangsu Key Lab Meteorol Observat & Radar Technol Nanjing 211006 Jiangsu Peoples R China

Millimeter waves have been recognized as carriers for 5G cellular networks. We carried out a series of millimeter-wave measurements in Beijing, China, and studied the atmospheric impacts on millimeter-wave transmission. Our measurement design is an exemplary LOS transmission link. We also studied a 3 km long commercial E-band millimeter-wave backhaul link in Goteborg, Sweden. We monitored the variation of received signal in the rain, and compared the theoretical rain-induced signal attenuation with the practically monitored signal attenuation. Our results show that there is 1.5-4.5 dB uncertainty between the practical and theoretical rain-induced signal attenuation. Assuming the prediction of rain intensity is available, we have proposed a novel rain-aware radio resource management strategy which adapts the modulation and coding schemes of an OFDM system to rainfall events. We have applied the proposed algorithm to an OFDM - based 5G system, and the throughput result is improved. The result shows that the throughput of a fixed modulation and coding scheme system is between 12%-95% of the system employing the proposed algorithm during rainfall events.

关键词： Atmospheric attenuation millimeter-wave radio propagation meteorological impact radio resource management adaptive modulation and coding 5G

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Wireless Transmission of Big Data: A Transmission Time Analysis Over Fading Channel

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2018年第7期17卷 4315-4325页

作者： Wang, Wen-Jing Yang, Hong-Chuan Alouini, Mohamed-Slim Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 2Y2 Canada King Abdullah Univ Sci & Technol Comp Elect & Math Sci & Engn Div Thuwal 23955 Saudi Arabia

In this paper, we investigate the transmission time of a large amount of data over fading wireless channel with adaptive modulation and coding (AMC). Unlike traditional transmission systems, where the transmission time of a fixed amount of data is typically regarded as a constant, the transmission time with AMC becomes a random variable, as the transmission rate varies with the fading channel condition. To facilitate the design and optimization of wireless transmission schemes for big data applications, we present an analytical framework to determine statistical characterizations for the transmission time of big data with AMC. In particular, we derive the exact statistics of transmission time over block fading channels. The probability mass function and the cumulative distribution function of transmission time are obtained for both slow and fast fading scenarios. We further extend our analysis to the Markov channel, where transmission time becomes the sum of a sequence of exponentially distributed time slots. Analytical expression for the probability density function of transmission time is derived for both fast fading and slow fading scenarios. These analytical results are essential to the optimal design and the performance analysis of future wireless transmission systems for big data applications.

关键词： Transmission time adaptive modulation and coding block fading Markov channel distribution functions

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