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QoS-Based Cross-Layer Scheduling for Wireless Multimedia Transmissions with adaptive modulation and coding

IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第11期61卷 4526-4538页

作者： Chen, Hui Chan, Henry C. B. Chan, Chi-Kong Leung, Victor C. M. Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada Hong Kong Polytech Univ Dept Comp Hong Kong Hong Kong Peoples R China

It is challenging to design effective scheduling algorithms for multimedia transmissions over wireless channels that employ adaptive modulation and coding (AMC). On the one hand, it is desirable for the overall system throughput to be enhanced by taking advantage of multi-user diversity. On the other hand, fairness or QoS guarantees need to be maintained for individual users, especially in the case of multimedia applications that have strict delay requirements. In this paper, we propose a novel scheduling algorithm called QoS-based cross-layer scheduling (QoS-CLS) to achieve a good design tradeoff. To maximize the system throughput, the algorithm takes into account the information on both the physical layer and the data link layer to schedule user transmissions. Using cross-layer information, the scheduling problem is formulated as a Markov Decision Process and the optimal decision policy (based on the channel status, traffic state, and buffer status of each traffic flow) is pre-calculated by linear programming. This policy is then stored in the system for scheduling in real-time. Simulation results show that QoS-CLS can greatly enhance the channel throughput compared to existing algorithms because of its cross-layer QoS consideration and the optimization method. Moreover, it can provide QoS guarantees while achieving efficient resource sharing among different traffic flows.

关键词： adaptive modulation and coding multimedia transmission scheduling

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A cross-layer optimized adaptive modulation and coding scheme for transmission of streaming media over wireless links

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WIRELESS NETWORKS 2010年第4期16卷 903-914页

作者： Vassilaras, Spyridon Athens Informat Technol Athens 19002 Greece

In this paper, a novel cross-layer adaptive modulation and coding scheme that optimizes the overall packet loss (by both transmission errors and excessive delays) probability under a given arrival process is developed. To this end, an improved Large Deviations approximation for the fraction of packets that suffer from excessive queuing delay is proposed. This approximation is valid for G/G/1 queues with infinite buffers that are driven by stationary arrival and service processes which satisfy certain conditions. Such models can capture the time correlations in the amount of traffic generated by streaming media sources and the time varying service capacity of a wireless link. Through numerical examples, the proposed AMC policy is shown to achieve a significant reduction in the overall packet loss rate compared to previously proposed schemes. This algorithmic performance gain can be translated into a sizeable decrease in the required transmit power or an analogous increase in the rate of the arrival process, subject to a given maximum packet loss rate Quality of Service constraint. Furthermore, the proposed AMC policy can be combined with ARQ in order to achieve an even lower overall packet loss probability.

关键词： adaptive modulation and coding Cross-layer Optimization Large Deviations Wireless Transmission of Streaming Media QoS ARQ

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Performance analysis of adaptive modulation and coding combined with transmit diversity in next generation mobile communication systems

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FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE 2004年第2期20卷 189-196页

作者： Hwang, I Jang, TW Kang, MG No, S Son, J Hong, DS Kang, CE Yonsei Univ Seoul 120749 South Korea Hanshin Univ Osan South Korea Korea Inst Sci & Technol Seoul South Korea

In this paper, we combine adaptive modulation and coding (AMC) with Transmit Diversity (TD) to improve the performance of AMC in CDMA systems. An improved SNR increases a probability of selecting modulation and coding Scheme (MCS) level that supports higher data transfer rate. Therefore, higher average throughput can be achieved. As an open-loop TD, Space-Time block coding based Transmit antenna Diversity (STTD) is applied to AMC. For a closed-loop TD, Selection Transmit Diversity (STD) is combined with AMC. The results show that higher throughput is achieved by AMC-TD schemes. Compared to the conventional AMC, AMC-STTD scheme shows about 250 kbps increase in throughput. In addition, AMC-STD with two transmit antennas achieves about 420 kbps throughput improvement over the conventional AMC at 9 dB SNR in flat Rayleigh fading channel. (C) 2003 Published by Elsevier B.V.

关键词： adaptive modulation and coding Transmit Diversity modulation and coding Scheme

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Slow and fast adaptive modulation and coding for uplink massive MIMO systems with packet retransmission

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IET COMMUNICATIONS 2022年第9期16卷 915-928页

作者： Radbord, Amin Harsini, Jalil S. Univ Guilan Dept Elect Engn POB *** Rasht Iran

Here, the authors consider the uplink of a cellular massive multiple-input multiple-output (MIMO) system with maximum ratio combiner (MRC) at base stations (BSs). To achieve a better QoS provisioning, users in the cells employ link adaptation using adaptive modulation and coding (AMC) in conjunction with packet retransmission. The authors present a cross-layer approach for the AMC design exploiting the time variation feature of MIMO wireless channels. At first, a fast AMC (FAMC) scheme is proposed to adapt the fast small-scale fading of the wireless channel based on the instantaneous channel state information. Since the fast fading is asymptotically averaged out due to the channel hardening property of massive MIMO system, we then suggest a slow AMC (SAMC) scheme which adjusts the adaptation parameters based on only the large-scale channel fading statistics including shadow fading and pass loss of the channel. The SAMC substantially reduces the feedback rate and implementation cost because of using a larger coherence time compared to that of the FAMC. For the proposed schemes, the probability density function of signal-to-interference-plus-noise ratio (SINR) for MRC receivers at BSs is analytically derived and verified by simulation. Also, closed-form expressions are presented for the throughput and packet error outage of the system. Index Terms-Massive MIMO, MRC, AMC, ARQ, Performance analysis.

关键词： adaptive modulation MRC receivers fading channels cellular massive MIMO system MRC adaptive modulation and coding probability density function MIMO wireless channels maximum ratio combiner modulation coding packet error outage MIMO communication telecommunication network reliability AMC design signal-to-interference-plus-noise ratio diversity reception cellular radio radiofrequency interference cellular massive multiple-input multiple-output system quality of service FAMC scheme probability QoS packet retransmission uplink massive MIMO systems

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Performance analysis of SNR threshold-setting strategies for adaptive modulation and coding under fading channels

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PHYSICAL COMMUNICATION 2018年 30卷 154-166页

作者： Lopez-Benitez, Miguel Univ Liverpool Dept Elect Engn & Elect Liverpool Merseyside England

adaptive modulation and coding (AMC) is a popular technique that dynamically adapts the employed modulation and coding Scheme (MCS) to the instantaneous channel quality, typically expressed in terms of the instantaneous Signal-to-Noise Ratio (SNR). The optimum MCS is selected based on a set of SNR thresholds, which define the range of SNR values on which each MCS is employed. The calculation of the SNR thresholds is a key aspect in the design and performance of AMC. This work performs a detailed and rigorous analysis of SNR threshold setting strategies for AMC, not only considering conventional methods commonly used in the literature but also proposing new methods to attain specific performance targets in terms of error rate, delay and spectral/energy efficiency. Closed-form expressions for these performance metrics are analytically derived under Rayleigh fading and employed to comparatively assess the performance of the considered solutions. The obtained results demonstrate that the proposed SNR threshold setting methods provide significant improvements in terms of error rate, delay and spectral/energy efficiency with respect to traditional methods. (C) 2018 Elsevier B.V. All rights reserved.

关键词： adaptive modulation and coding Link adaptation Rayleigh fading LTE

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Joint Power Management and adaptive modulation and coding for Wireless Communications Systems With Unreliable Buffering Memories

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2014年第8期61卷 2456-2465页

作者： Khairy, Muhammad S. Khajeh, Amin Eltawil, Ahmed M. Kurdahi, Fadi J. Univ Calif Irvine Dept Elect Engn & Comp Sci Irvine CA 92697 USA Intel Labs Hillsboro OR 97006 USA

To guard against process variability in advanced semiconductor nodes, especially for high-density memories, designers resort to overdesigning policies resulting in increased power consumption. A promising approach to save power is to utilize Voltage over-Scaling (VoS). However VoS results into unreliable buffering memories where a predictable statistically amount of errors are introduced to memories. The goal is to trade off channel dependent SNR slack versus hardware induced errors, to achieve predetermined quality metrics, at reduced power consumption. By design, modern communication systems attempt to minimize channel-dependent SNR slack via adaptive modulation and coding (AMC) schemes, thus reducing the gains of on-chip power management. This paper investigates the interaction between on-chip power management via VoS on embedded memories versus network based AMC techniques. A novel mathematical approach that analytically describes the system packet error rate (PER) performance under the VoS induced noise is presented. Based on this model, different AMC and power management algorithms are presented that utilize the received SNR estimates to find the best AMC mode and memory voltage that achieves performance goals at reduced power consumption. Simulation results show that the proposed algorithms can achieve up to 58% energy efficiency for the memory-subsystems compared to conventional AMC algorithm with perfect memories.

关键词： adaptive modulation and coding dynamic power management embedded memories energy efficient systems low power voltage over scaling

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Random neural network based cognitive engines for adaptive modulation and coding in LTE downlink systems

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COMPUTERS & ELECTRICAL ENGINEERING 2017年 57卷 336-350页

作者： Adeel, Ahsan Larijani, Hadi Ahmadinia, Ali Glasgow Caledonian Univ Sch Engn & Built Environm Glasgow G4 0BA Lanark Scotland Calif State Univ San Marcos Comp Sci & Informat Syst Dept San Marcos TX USA

This paper presents two random neural network (RNN) based context-aware decision making frameworks to improve adaptive modulation and coding (AMC) in long-term evolution (LTE) downlink systems. In the first framework, AMC is modelled as a traditional classification problem with the aim to maximize the probability of correct classification. The second framework seeks to optimize the throughput as opposed to simply maximizing the probability of the correct classification. To model the second framework, we developed a hybrid cognitive engine (CE) architecture by integrating an RNN based learning algorithm with genetic algorithm (GA) based reasoning. RNN inherent properties help CE to comply with the essential CE design requirement (i.e. concurrent long-term-learning, low computational complexity, and fast decision making). The performance of RNN is compared with artificial neural networks (ANN) and state-of-the-art effective exponential SINR mapping (EESM) algorithm. A comprehensive analysis of the proposed RNN based AMC scheme is presented by jointly incorporating the effect of different schedulers, feedback delays, and multi-antenna diversity on the throughput of an orthogonal frequency-division multiple access (OFDMA) system. The critical analysis of the first framework revealed that RNN based CE can achieve comparable results with faster adaptation, even in severe environment changes without the need of retraining compared to ANN. The analysis of the second approach demonstrated RNNs faster adaptation as compared to ANN and showed upto 253% gain in user throughput. RNN based CE efficiently exploited the channel quality information feedback delay to improve system throughput and helped cell-edge and cell-centre users to experience much better services in terms of achieved throughput as compared to EESM. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Random neural network Context-aware decision making adaptive modulation and coding Long-term evolution Hybrid cognitive engine Genetic algorithm

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Throughput enhancement of RIS and STARRIS using adaptive modulation and coding for 6G systems

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INTERNATIONAL JOURNAL OF AD HOC AND UBIQUITOUS COMPUTING 2024年第4期46卷 195-202页

作者： Halima, Nadhir Ben Sheikh, Sajid Mubashir Community Coll Qatar Dept Informat Technol Doha 7344 Qatar Univ Botswana Dept Elect Engn Private Bag UB 0061 Gaborone Botswana

In this article, the throughput of reconfigurable intelligent surfaces (RIS) is improved using adaptive modulation and coding (AMC). The best modulation and coding scheme (MCS) is selected at the transmitter using the instantaneous signal to noise ratio (SNR) measured at the receiver and sent back on the feedback channel. RIS is placed between the transmitter and the receiver so that the SNR is maximised at the receiver side as RIS reflections are combined coherently at the receiver and results in significant spatial diversity. All reflections on RIS have a zero phase at the receiver. We show that RIS using AMC offers a larger throughput than conventional RIS with fixed MCS for all SNR range. RIS with AMC offers 48, 42, 36, 30, 24, 18 dB gain for N = 256, 128, 64, 32, 16, 8 reflectors. We obtained 10 dB gain when RIS uses AMC versus 256-QAM. We also improve the throughput of Simultaneously Transmitting And Reflecting RIS (STARRIS) using AMC. We obtained 13 dB gain when STARRIS uses AMC versus 256-QAM.

关键词： adaptive modulation and coding AMC reconfigurable intelligent surfaces RIS modulation and coding scheme MCS throughput enhancement 6G

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Link Adaptation Based on adaptive modulation and coding for Multiple-Antenna OFDM System

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2008年第8期26卷 1599-1606页

作者： Tan, Peng Hui Wu, Yan Sun, Sumei ASTAR Inst Infocomm Res Singapore Singapore

In this paper, we study the problem of link adaptation based on adaptive modulation and coding for multiple-antenna OFDM system in slow fading channel. Based on the extrinsic information transfer analysis, we give an accurate packet error rate prediction with channel estimation errors. This method uses Gaussian approximation to characterize the output of the detector and decoder. We also discuss approaches for searching and selecting the best modulation and coding scheme for the link adaptation algorithm. Finally, the performance of the proposed link adaptation algorithm is studied for the IEEE 802.11n multiple-antenna OFDM system. Good system throughput are achieved using the proposed method, compared to the SNR based algorithm

关键词： MIMO-OFDM adaptive modulation and coding Gaussian approximation PER prediction

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A Cross-Layer adaptive modulation and coding Scheme for Energy Efficient Software Defined Radio

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JOURNAL OF SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY 2012年第1期69卷 23-30页

作者： Chen, Ying Davis, Linda M. Univ S Australia Inst Telecommun Res Adelaide SA 5001 Australia

In this paper, a simple and novel cross-layer adaptive modulation and coding (AMC) scheme, which increases the energy efficiency of the wireless communication system is proposed. Traditionally, AMC has been used to improve MAC-layer performance in terms of coded bit error rate, packet error rate, and throughput. The modulation and coding scheme is switched according to signal-to-noise ratio thresholds at the PHY layer. We extend the approach, proposing a framework for energy-efficient cross-layer AMC that captures the impact of both MAC layer and PHY layer parameters on the AMC switching criteria. Cross-layer designs are naturally suited to software defined radio applications. Not only are they readily implemented in software, but also they are integral to the radio components. They can optimize performance of the radio either for a given configuration or adaptively. Through examples of WLAN physical layer and Frequency Domain Equalized systems, we demonstrate our AMC scheme and verify its effectiveness by simulation.

关键词： Software defined radio Cross-layer design Energy efficiency adaptive modulation and coding

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