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Integrated scheduling and link adaptation for heterogeneous networks: design and performance analysis

INTERNATIONAL JOURNAL OF ELECTRONICS 2020年第7期107卷 1098-1126页

作者： Taki, Mehrdad Nezafati, Mohammad Bagher Univ Qom Dept Elect Engn Qom Iran Inst Res Fundamental Sci Tehran Iran

This paper presents novel integrated scheduling and link adaptation (ISLA) schemes for links which have a common spectrum and possibly different rates and reliability constraints. We consider the problem of weighted sum average rate maximisation of wireless links. In an orthogonal transmission system, a link is selected using instantaneous signal-to-noise (SNR) of all the links, and its rate and power are set in a jointly optimised manner. To demonstrate the effectiveness of the proposed approach, we analyse ISLA schemes with continuous rate adaptation using constant or adaptive transmission powers. ISLA schemes are designed in similar settings for practical discrete rate-adaptive systems using adaptive modulation and coding. To this end, a design framework is presented, which relies on a partitioning of space of links' SNRs into regions, similar to structured vector quantisation. Within this framework, a particular ISLA design with high performance and polynomial complexity is suggested. The proposed schemes are designed before the start of the transmission, based on closed-form solutions, and can easily be applied to multiple access or broadcast networks. We also analyse several schemes for comparison, which employ modified Round-Robin, opportunistic scheduling or online generalised scheduling. Numerical results demonstrate how the proposed ISLA schemes outperform the benchmark schemes and effectively meet various user requirements.(1)

关键词： Cross-layer design and optimisation adaptive modulation and coding rate and power allocation optimised scheduling link adaptation

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Nonlinearity-Tolerant Four-Dimensional 2A8PSK Family for 5-7 Bits/Symbol Spectral Efficiency

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2017年第8期35卷 1383-1391页

作者： Kojima, Keisuke Yoshida, Tsuyoshi Koike-Akino, Toshiaki Millar, David S. Parsons, Kieran Pajovic, Milutin Arlunno, Valeria Mitsubishi Elect Res Labs Cambridge MA 02139 USA Acacia Commun Maynard MA 01754 USA Chalmers Univ Technol Dept Microtechnol & Nanosci SE-41296 Gothenburg Sweden

We describe in detail the recently proposed four-dimensional modulation format family based on 2-ary amplitude 8-ary phase-shift keying (2A8PSK), supporting spectral efficiencies of 5, 6, and 7 bits/symbol. These formats nicely fill the spectral efficiency gap between the dual-polarization (DP) quadrature PSK (QPSK) and DP 16-ary quadrature-amplitude modulation (16QAM), with excellent linear and nonlinear performance. Since these modulation formats just use different parity bit expressions in the same constellation, similar digital signal processing can be seamlessly used for different spectral efficiency. A series of nonlinear transmission simulation results shows that this modulation format family outperforms the conventional modulation formats at the corresponding spectral efficiency. We also investigate the adaptive equalizer for these modulation formats.

关键词： adaptive modulation and coding high-dimensional modulation format nonlinearity tolerance spectral efficiency

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Dynamic Fractional Frequency Reuse (DFFR) with AMC and Random Access in WiMAX System

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WIRELESS PERSONAL COMMUNICATIONS 2013年第4期68卷 1871-1881页

作者： Mohades, Zohreh Vakili, Vahid Tabataba Razavizadeh, S. Mohammad Abbasi-Moghadam, Dariush IUST Sch Elect Engn Dept Telecommun Tehran Iran IUST Dept Elect Engn Tehran Iran Shahid Bahonar Univ Dept Elect Engn Kerman Iran

In this paper;dynamical resource allocation scheme is proposed to improve throughput and fairness in the modern broadband wireless systems such as IEEE 802.16 Worldwide Interoperability for Microwave Access. To assign the subcarriers to users, dynamic fractional frequency reuse is used. In dynamic fractional frequency reuse, each cell is partitioned into two regions, one called super region and another called regular region. Regular region is divided into 3 parts which correspond to the three sectors. In this method, a utility function is firstly used for the subcarrier allocation to the geographical regions and then opportunistic scheduling is applied for the assignment subcarriers to users in each cell. In order to increase the throughput of the system, adaptive modulation and coding techniques are used. Using dynamic fractional frequency reuse reduces fairness among users of a cell. Therefore a random access sub-band is applied to improve the fairness of the system.

关键词： Dynamic fractional frequency reuse WiMAX Inter cell interference adaptive modulation and coding Random access

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adaptive scheduling for MIMO wireless networks:: Cross-layer approach and application to HSDPA

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第1期6卷 259-268页

作者： Aniba, Ghassane Aissa, Sonia EMT INRS Montreal PQ H5A 1K6 Canada

In this paper, we consider the scheduling problem in multiple-input multiple-output (MIMO) wireless networks. The main important characteristic of an optimal scheduler is to maximize throughput while servicing users in a fair manner. Herein, we formulate MIMO scheduling as a Generalized Assignment Problem (GAP) and propose a general solution for the GAP, namely, a Cross-Layer MIMO scheduler (CMS), which uses a novel adaptive Proportional Fairness (APF) mapping approach in conjunction with a new Fast Transmit Antenna Selection (FTAS) technique, to determine the set of users to transmit to and the antenna over which the data associated to each user should be transmitted. The proposed scheduler is applied for packet transmission in High-Speed Downlink Packet Access (HSDPA), taking advantage of the use of adaptive modulation and coding while coping with the constraints on the maximum number of simultaneous codes a user equipment can support, the limited uplink signalling, and the absence of fast power control. Numerical results show that the proposed CMS provides up to 70% increase in total throughput compared to other scheduling schemes.

关键词： adaptive modulation and coding antenna selection cross-layer design HSDPA MIMO systems scheduling

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Cross-layer-based adaptive TCP algorithm for cloud computing services in 4G LTE-A relaying communication

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WIRELESS NETWORKS 2016年第8期22卷 2579-2595页

作者： Chang, Ben-Jye Li, Yi-Hsuan Chen, Shin-Pin Liang, Ying-Hsin Natl Yunlin Univ Sci & Technol Dept Comp Sci & Informat Engn Yunlin Taiwan Nan Kai Univ Technol Dept Multimedia Animat & Applicat Nantou Taiwan

Cloud computing provides various diverse services for users accessing big data through high data rate cellular networks, e.g., LTE-A, IEEE 802.11ac, etc. Although LTE-A supports very high data rate, multi-hop relaying, and cooperative transmission, LTE-A suffers from high interference, path loss, high mobility, etc. Additionally, the accesses of cloud computing services need the transport layer protocols (e.g., TCP, UDP, and streaming) for achieving end-to-end transmissions. Clearly, the transmission QoS is significantly degraded when the big data transmissions are done through the TCP protocol over a high interference LTE-A environment. The issue of providing high data rate and high reliability transmissions in cloud computing needs to be addressed completely. Thus, this paper proposes a cross-layer-based adaptive TCP algorithm to gather the LTE-A network states (e.g., AMC, CQI, relay link state, available bandwidth, etc.), and then feeds the state information back to the TCP sender for accurately executing the network congestion control of TCP. As a result, by using the accurate TCP congestion window (cwnd) under a high interference LTE-A, the number of timeouts and packet losses are significantly decreased. Numerical results demonstrate that the proposed approach outperforms the compared approaches in goodput and fairness, especially in high interference environment. Especially, the goodput of the proposed approach is 139.42 % higher than that of NewReno when the wireless loss increases up to 4 %. Furthermore, the throughput and the response functions are mathematically analyzed. The analysis results can justify the claims of the proposed approach.

关键词： LTE-A Multiple-hop relaying Cross-layer adaptive modulation and coding Congestion control TCP reliable transmission

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Physical-Layer adaptive Resource Allocation in Software-Defined Data Center Networks

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JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2018年第12期10卷 1015-1026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

With the deep physical-layer programmability enabled by software-defined networking (SDN), it is now feasible to realize optical data center transceivers that adapt their transmission parameters in response to time-varying traffic demand and signal quality conditions. In this paper, we develop a cross-layer performance tuning framework for wavelength-tunable data center transceivers, combining scalable and secure modulation order and code rate adaptation. We develop new physical-layer control modules and combine SDN control with distributed preamble encoding in order to achieve both rate adaptation and node synchronization in a wavelength-routing data center testbed. Our experimental and theoretical studies based on pulse amplitude modulation and low-density parity-check coding point to the significance of joint modulation order and code-rate adaptation in data centers. We report real-time resource adaptation with switching speeds on the order of hundreds of milliseconds.

关键词： adaptive modulation and coding Data center Preamble encoding Pulse amplitude modulation (PAM) Software-defined networking (SDN) Wavelength routing

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Hybrid Neural Network-Based Fading Channel Prediction for Link Adaptation

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IEEE ACCESS 2021年 9卷 117257-117266页

作者： Eom, Chahyeon Lee, Chungyong Yonsei Univ Sch Elect & Elect Engn Seoul 03722 South Korea

We propose an artificial intelligence-based channel prediction scheme that can potentially facilitate link adaptation in customized communication systems. Link adaptation is a key process for wireless communication that requires accurate channel state information (CSI). However, the CSI may be outdated because of computational and propagation delays. In addition, a subframe with no CSI reference signal cannot provide CSI feedback. The proposed scheme solves these problems by predicting future channels. Although traditional stochastic methods suffer from marginal prediction accuracy or unacceptable computational complexity, neural networks allow time series prediction for channels even considering constraints for practical application. We introduce a hybrid architecture for improving the prediction accuracy of the neural network when extracting meaningful features. The proposed scheme uses a single hybrid network that can predict channels in different environments. Simulations were performed using a spatial channel model to evaluate the performance at the system-level, and the results indicated that the proposed scheme effectively increases the prediction accuracy for the channel quality indicator and spectral efficiency.

关键词： Predictive models OFDM Antenna arrays Delays Channel estimation Adaptation models Recurrent neural networks adaptive modulation and coding artificial intelligence channel prediction customized communication system link adaptation neural network sixth generation

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Novel resource allocation algorithms for multiuser downlink MIMO-OFDMA of FuTURE B3G systems

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Progress in Natural Science:Materials International 2009年第9期19卷 1141-1146页

作者： Qiaoyun Sun, Hui Tian *, Shuang Wang, Kun Dong, Ping Zhang Key Laboratory of Universal Wireless Communication, Ministry of Education, Wireless Technology Innovation Institute, Beijing University of Posts & Telecommunications, Beijing 100876, China Key Laboratory of Universal Wireless Communication Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts & Telecommunications Beijing 100876 China

In this paper, subcarrier and power allocation problems for multiuser downlink MIMO-OFDMA of the FuTURE B3G TDD system are investigated. For the reciprocity of the TDD channel, the channel state information can be employed at the transmitter, thus eigen beamforming can be implemented efficiently. With the goal of minimizing the total transmit power under the condition that the QoS requirement of each user can be guaranteed, a novel dynamic resource allocation scheme is proposed to exploit the multiuser diversity gain. The proposed algorithm involves adaptive subcarrier allocation, adaptive modulation and eigen beamforming and achieves significant improvement in overall system performance. Based on the proposed scheme, a modified bit and power allocation is developed. The modified scheme reduces the computational complexity at little expense of system performance. Numerical simulations show that the proposed algorithm and the modified scheme can decrease the total transmit power effectively.

关键词： adaptive modulation and coding Dynamic resource allocation Eigen beamforming MIMO–OFDMA

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Wireless Channel State-Aware and adaptive Epidemic Dissemination in Ad Hoc Networks

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INTERNATIONAL JOURNAL OF WIRELESS INFORMATION NETWORKS 2014年第1期21卷 58-67页

作者： Kontos, Theofanis Anagnostopoulos, Christos Hadjiefthymiades, Stathes Univ Athens Pervas Comp Athens Greece Ionian Univ Dept Informat Corfu Greece Univ Glasgow Sch Comp Sci Glasgow Lanark Scotland Univ Aegean Dept Informat & Commun Syst Engn Mitilini Greece

Ad hoc networks are characterized by limited resources (e.g. energy, bandwidth). Efficient information dissemination while avoiding excessive energy cost can be achieved through the suitable design of a network. To this end we propose an information dissemination scheme which couples epidemic dissemination with adaptive modulation and coding (AMC). The proposed scheme tunes the message forwarding probability and the coding and modulation mode in order to achieve a balance between maximum coverage over the network and minimum energy expenditure. We achieve this based on the evaluation of suitably defined indicators related to the lower network layers and exploiting information on the current status of the wireless medium. Building on established previous AMC-related work, our simulation results indicate that our scheme brings significant improvement over non-adaptive approaches, comparable with other adaptive epidemic dissemination schemes. Our findings are quite promising for adaptive epidemic-based information dissemination schemes with a strong cross-layer component.

关键词： Epidemic information dissemination adaptive probabilistic information dissemination Ad hoc networks adaptive modulation and coding

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Throughput of HARQ Protocols on a Block Fading Channel

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IEEE COMMUNICATIONS LETTERS 2010年第3期14卷 257-259页

作者： Lagrange, Xavier Univ Europeenne Bretagne Inst Telecom Telecom Bretagne Bretagne France

This letter considers hybrid automatic repeat request (HARQ) protocols on a block Rayleigh fading channel. We derive the packet loss probability and the throughput for HARQ in closed-form. We propose a simple approximated but very accurate formula for the throughput. We deduce a cross-layer design of adaptive modulation and coding with HARQ.

关键词： Hybrid automatic repeat request adaptive modulation and coding cross-layer design wireless networks fading channels

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