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Cross Layer AMC Scheduling for a Cooperative Wireless Communication System over Nakagami-m Fading Channels

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2012年第6期11卷 2330-2341页

作者： Wang, Ning Gulliver, T. Aaron Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 3P6 Canada

We study a single-source single-destination cooperative wireless communication system with multiple relays operating in a modified decode-and-forward mode. Nakagami-m fading with additive white Gaussian noise is assumed for all internode channels. The bursty data packet arrival is modeled by a Markov-modulated Poisson process (MMPP). A packet feedback model is proposed to characterize packet loss in the wireless channel. An approximation to the steady state distribution of the proposed generalized discrete time M/G/1-type queue at the source is obtained by state truncation. Packet level performance of four transmission modes adopting different modulation and coding schemes is analyzed under a variety of channel and traffic conditions using the truncated queueing analysis. The network power is used as a criterion to find boundary curves of adaptive modulation and coding (AMC) scheduling for the cooperative wireless system. Two source node transmission protocols, namely the transmit-every-clock-tick (TREC) and the LAZY protocols, are examined for both the AMC scheduling and channel utilization analysis.

关键词： adaptive modulation and coding cooperative communications Nakagami-m fading network power packet feedback queueing model relay channel

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Cross-Layer Fast Link Adaptation for MIMO-OFDM Based WLANs

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WIRELESS PERSONAL COMMUNICATIONS 2011年第3期56卷 599-609页

作者： Martorell, Gabriel Riera-Palou, Felip Femenias, Guillem Univ Balearic Isl Dept Math & Informat Mobile Commun Grp Mallorca 07122 Spain

This paper considers the use of cross-layer fast link adaptation (FLA) for WLANs employing a MIMO-OFDM physical layer. A packet error rate (PER)-based FLA technique that, without loss of generality, makes use of the exponential effective SNR mapping (EESM) is proposed. Additionally, an FLA scheme relying on bit error rate (BER) metrics is introduced that simplifies the link adaptation procedure without any significant performance degradation. Results show that both PER- and BER-based FLA techniques optimize the data throughput while satisfying prescribed quality of service constraints. Channel estimation errors have also been considered, revealing the importance of good channel estimators in order for FLA strategies to work satisfactorily.

关键词： Fast link adaptation MIMO-OFDM IEEE 802.11n Link quality metrics Cross-layer design adaptive modulation and coding

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Cross-layer modeling of adaptive wireless links for QoS support in heterogeneous wired-wireless networks

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WIRELESS NETWORKS 2006年第4期12卷 427-437页

作者： Liu, Qingwen Zhou, Shengli Giannakis, Georgios B. Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA Univ Connecticut Dept Elect & Comp Engn Storrs CT 06269 USA

Future wired-wireless multimedia networks require diverse quality-of-service (QoS) support. To this end, it is essential to rely on QoS metrics pertinent to wireless links. In this paper, we develop a cross-layer model for adaptive wireless links, which enables derivation of the desired QoS metrics analytically from the typical wireless parameters across the hardware-radio layer, the physical layer and the data link layer. We illustrate the advantages of our model: generality, simplicity, scalability and backward compatibility. Finally, we outline its applications to power control, TCP, UDP and bandwidth scheduling in wireless networks.

关键词： cross-layer design quality of service adaptive modulation and coding queuing analysis

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Blind Estimation of Code Parameters for Product Codes Over Noisy Channel Conditions

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2020年第2期56卷 1460-1473页

作者： Swaminathan, R. Madhukumar, A. S. Wang Guohua Indian Inst Technol IIT Indore Discipline Elect Engn Indore 53552 Madhya Pradesh India Nanyang Technol Univ Sch Comp Sci & Engn Singapore 639798 Singapore Nanyang Technol Univ Temasek Labs Singapore 639798 Singapore

Product codes are multidimensional codes constructed using multiple component codes. In this paper, novel algorithms are proposed for the blind estimation of two-dimensional product code parameters over the noisy channel conditions considering Reed-Solomon and Bose-Chaudhuri-Hocquenghem as component codes. The performance of the algorithms in terms of probability of the correct estimation is investigated for different code parameters. It is observed that the accuracy improves with the decrease in modulation order and code dimension values.

关键词： Product codes Estimation Noise measurement Channel estimation Synchronization modulation Decoding adaptive modulation and coding Bose-Chaudhuri-Hocquenghem (BCH) codes blind estimation noncooperative communication product codes reconfigurable radio Reed-Solomon (RS) codes signals intelligence

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An Accurate Model for EESM and its Application to Analysis of CQI Feedback Schemes and Scheduling in LTE

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第10期10卷 3436-3448页

作者： Donthi, Sushruth N. Mehta, Neelesh B. IISc Dept Elect Commun Eng Bangalore Karnataka India

The Effective Exponential SNR Mapping (EESM) is an indispensable tool for analyzing and simulating next generation orthogonal frequency division multiplexing (OFDM) based wireless systems. It converts the different gains of multiple subchannels, over which a codeword is transmitted, into a single effective flat-fading gain with the same codeword error rate. It facilitates link adaptation by helping each user to compute an accurate channel quality indicator (CQI), which is fed back to the base station to enable downlink rate adaptation and scheduling. However, the highly non-linear nature of EESM makes a performance analysis of adaptation and scheduling difficult;even the probability distribution of EESM is not known in closed-form. This paper shows that EESM can be accurately modeled as a lognormal random variable when the subchannel gains are Rayleigh distributed. The model is also valid when the subchannel gains are correlated in frequency or space. With some simplifying assumptions, the paper then develops a novel analysis of the performance of LTE's two CQI feedback schemes that use EESM to generate CQI. The comprehensive model and analysis quantify the joint effect of several critical components such as scheduler, multiple antenna mode, CQI feedback scheme, and EESM-based feedback averaging on the overall system throughput.

关键词： Effective exponential SNR mapping (EESM) long term evolution (LTE) orthogonal frequency division multiplexing (OFDM) channel quality feedback multiple antenna diversity frequency-domain scheduling adaptive modulation and coding lognormal random variable

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Design and Optimization for VoD Services With adaptive Multicast and Client Caching

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IEEE COMMUNICATIONS LETTERS 2017年第7期21卷 1621-1624页

作者： Feng, Hao Chen, Zhiyong Liu, Hui Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China

Multicast and prefix caching are two promising approaches to provide scalable video-on-demand (VoD) services. We contribute to solve the adaptive multicast delivery and the cache allocation problem for VoD services with client caching under asynchronous client requests. We first propose a client caching enabled adaptive multicast delivery scheme, which combines the stream merginglike method with prefix caching and adaptive modulation and coding, to fully exploit the multicast opportunity among asynchronous requests from heterogeneous clients. Next, we derive the bandwidth consumption of the proposed delivery scheme under a given prefix cache allocation and Poisson arrival request. We then optimize the cache allocation to minimize the average bandwidth consumption, and the problem is proved to be convex and solved effectively. Finally, three extreme cases are studied to provide closed-form solutions and more insight on the cache allocation and the delivery scheme for VoD systems.

关键词： Multicast video-on-demand adaptive modulation and coding stream merging cache allocation

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Fast Reinforcement Learning for Energy-Efficient Wireless Communication

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2011年第12期59卷 6262-6266页

作者： Mastronarde, Nicholas van der Schaar, Mihaela Univ Calif Los Angeles Los Angeles CA 90095 USA

We consider the problem of energy-efficient point-to-point transmission of delay-sensitive data (e. g., multimedia data) over a fading channel. We propose a rigorous and unified framework for simultaneously utilizing both physical-layer and system-level techniques to minimize energy consumption, under delay constraints, in the presence of stochastic and unknown traffic and channel conditions. We formulate the problem as a Markov decision process and solve it online using reinforcement learning. The advantages of the proposed online method are that i) it does not require a priori knowledge of the traffic arrival and channel statistics to determine the jointly optimal physical-layer and system-level power management strategies;ii) it exploits partial information about the system so that less information needs to be learned than when using conventional reinforcement learning algorithms;and iii) it obviates the need for action exploration, which severely limits the adaptation speed and run-time performance of conventional reinforcement learning algorithms.

关键词： Energy-efficient wireless multimedia communication dynamic power management power-control adaptive modulation and coding Markov decision process reinforcement learning

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Interplay Between Optimal Selection Scheme, Selection Criterion, and Discrete Rate Adaptation in Opportunistic Wireless Systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第7期61卷 2735-2745页

作者： Mehta, Neelesh B. Talak, Rajat Suresh, Ananda T. Indian Inst Sci IISc Dept Elect Commun Eng ECE Bangalore Karnataka India Univ Calif San Diego Dept Elect & Comp Eng San Diego CA 92103 USA

An opportunistic, rate-adaptive system exploits multi-user diversity by selecting the best node, which has the highest channel power gain, and adapting the data rate to selected node's channel gain. Since channel knowledge is local to a node, we propose using a distributed, low-feedback timer backoff scheme to select the best node. It uses a mapping that maps the channel gain, or, in general, a real-valued metric, to a timer value. The mapping is such that timers of nodes with higher metrics expire earlier. Our goal is to maximize the system throughput when rate adaptation is discrete, as is the case in practice. To improve throughput, we use a pragmatic selection policy, in which even a node other than the best node can be selected. We derive several novel, insightful results about the optimal mapping and develop an algorithm to compute it. These results bring out the inter-relationship between the discrete rate adaptation rule, optimal mapping, and selection policy. We also extensively benchmark the performance of the optimal mapping with several timer and opportunistic multiple access schemes considered in the literature, and demonstrate that the developed scheme is effective in many regimes of interest.

关键词： Cross-layer design distributed selection discrete rate adaptation adaptive modulation and coding timer scheme fading channels multiple access collision net throughput

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Radio Resource Management for Green 3GPP Long Term Evolution Cellular Networks: Review and Trade-offs

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IETE TECHNICAL REVIEW 2013年第3期30卷 257-269页

作者： Salman, Mustafa Ismael Abdulhasan, Muntadher Qasim Ng, Chee Kyun Noordin, Nor Kamariah Sali, Aduwati Ali, Borhanuddin Mohd Univ Putra Malaysia Fac Engn Dept Comp & Commun Syst Engn Upm Serdang 43400 Selangor Darul Malaysia

Conventional design of cellular systems aims to maximize the system capacity and spectral efficiency due to sustainable growth of data rate requirements. As the energy consumption becomes relatively high, energy-efficient design for cellular systems is highly required to save energy as well as reducing the undesirable carbon dioxide emitted by these systems. However, reducing the energy consumption will degrade other system performances such as the data rate and quality of service. Therefore, joint optimization for overall system performances should be achieved. In this paper, the energy-efficient radio resource management (RRM) for Long Term Evolution (LTE) systems is addressed. After a brief introduction to LTE radio resource block and LTE frame, different types of energy efficiency metrics are defined to give a better understanding to the energy efficiency perspectives. The energy-efficient approaches related to link adaptation and RRM are explained. The state-of-the-art energy-efficient schedulers are also discussed, and a comprehensive comparison between them is adopted in this paper. Moreover, many trade-offs, challenges, and open issues are addressed to optimize the system performances.

关键词： adaptive modulation and coding Energy efficiency Green communication Link adaptation Multi-input-multi-output Orthogonal frequency division multiple access Resource allocation 3GPP long term evolution

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Reinforcement Learning Based adaptive Blocklength and MCS for Optimizing Age Violation Probability

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IEEE ACCESS 2023年 11卷 122411-122425页

作者： Ozkaya, Aysenur Topbas, Ahsen Ceran, Elif Tugce Aselsan Inc TR-06200 Ankara Turkiye Middle East Tech Univ Dept Elect & Elect Engn TR-06800 Ankara Turkiye

As a measure of the freshness of data, Age of Information (AoI) has become an essential performance metric in status update applications with stringent timeliness constraints. This study employs adaptive strategies to minimize the novel, information freshness-based performance metric age violation probability (AVP), the probability of the instantaneous age exceeding a predefined constraint, in short packet communications (SPC). AVP can be considered one of the key performance indicators (KPIs) in 5G Ultra-Reliable Low Latency Communications (URLLC), and it is expected to gain more importance in 6G technologies, especially in extreme URLLC (xURLLC). Two distinct approaches are considered: the first focuses on adaptively selecting the blocklengths with either imperfect or missing channel state information exploiting finite blocklength theory approximations. The second involves dynamically choosing the modulation and coding scheme (MCS) to minimize the AVP under stringent timeliness constraints and non-asymptotic information theory bounds. In the context of adaptive blocklength selection, state-aggregated value iteration, Q-learning algorithms, and finite blocklength theory approximations are leveraged to adjust blocklengths to achieve low age violation probabilities adaptively. The simulation results highlight the effectiveness of these algorithms in minimizing age violation probabilities compared to the fixed blocklengths under varying channel conditions. Additionally, constructing a deep reinforcement learning (DRL) framework, we propose a deep Q-network policy for the dynamic selection of the modulation and coding scheme among the available MCSs defined for URLLC systems. Through comprehensive simulations, we demonstrate the superiority of the proposed adaptive methods over traditional benchmark methods.

关键词： Measurement modulation Encoding Ultra reliable low latency communication Fading channels Throughput Minimization Information age Reinforcement learning Dynamic programming Age of information reinforcement learning dynamic programming finite blocklength adaptive modulation and coding

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