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Energy Minimization for Wireless Video Transmissions With Deadline and Reliability Constraints

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2013年第3期23卷 467-481页

作者： Chuah, Seong-Ping Chen, Zhenzhong Tan, Yap-Peng Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

In wireless video transmissions, encoded video frames are often large in data load and truncated into many transport packets (TPs) for reliable transmissions. These TPs are to be delivered before a deadline at certain reliability that depends on the importance of the video frame. High power and bitrate transmission schemes are often deployed to ensure low loss rate, but at the cost of substantial energy consumption. This paper addresses the energy-minimizing transmission policy for highly reliable transmissions of a group of TP with a common deadline. We jointly adapt the transmission rate, transmission power, and retransmission limit to minimize the transmission energy while ensuring that the video frame is reliably delivered before a deadline. In a slow fading channel, we formulate a deterministic transmission policy that allocates a retransmission limit to the TPs and jointly optimizes with the transmission bitrate and power. Contrary to the intuition that avoids packet loss and retransmission to preserve energy, we demonstrate that allowing some retransmissions in the joint optimization consumes less energy, without compromising the target reliability. In a Rayleigh fading channel, a conventional approach adopts a supportable transmission rate and declares off-channel at deep fading. We generalize the approach to include various transmission schemes at different fading states and propose the probabilistic combination of these schemes. Given the fading statistics and a channel state, our policy determines to pause or to deploy a proper transmission scheme such that the video frame transmission is energy minimized, timely, and highly reliable. Extensive simulations confirm that the proposed transmission policies consume less energy than existing methods. In particular, when the deadline or the target reliability are tightened, the proposed policies yield even higher energy efficiency.

关键词： Energy minimization modulation and coding scheme reliability constraint retransmission limit transmission deadline transmission power wireless video transmission

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Algorithm for Transmission Parameters Selection for Sporadic URLLC Traffic in Uplink

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JOURNAL OF COMMUNICATIONS TECHNOLOGY AND ELECTRONICS 2022年第12期67卷 1492-1499页

作者： Shashin, A. E. Belogaev, A. A. Krasilov, A. N. Khorov, E. M. HSE Univ Moscow 101000 Russia Russian Acad Sci Kharkevich Inst Informat Transmiss Problems Moscow 127051 Russia

Ultra-Reliable Low-Latency Communications (URLLC) is a key service for fifth generation (5G) cellular systems. Typical requirements for this service are transmission reliability above 99.999% and latency below 1 ms. The paper considers a scenario with sporadic URLLC traffic in the uplink. To satisfy the strict latency requirements, user equipments (UEs) use the grant-free channel access method. According to this method, the base station allocates time-frequency resources and selects transmission parameters (i.e., the modulation and coding scheme, number of transmission attempts) in advance for each UE. To provide high resource utilization in the case of sporadic traffic, the base station allocates shared channel resources to several UEs, which can lead to interference between transmissions of different UEs. The paper proposes an algorithm for selection of transmission parameters for each UE that takes into account the channel conditions of each considered UE and the interference caused by transmissions of other UEs. Numerical results obtained with NS-3 show that the proposed algorithm increases the network capacity up to six times with respect to the algorithms presented in the literature.

关键词： cellular systems 5G URLLC sporadic traffic uplink modulation and coding scheme simulation network capacity

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SmartCon: Deep Probabilistic Learning-Based Intelligent Link-Configuration in Narrowband-IoT Toward 5G and B5G

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IEEE TRANSACTIONS ON COGNITIVE COMMUNICATIONS AND NETWORKING 2022年第2期8卷 1147-1158页

作者： Karmakar, Raja Kaddoum, Georges Chattopadhyay, Samiran Univ Quebec Dept Elect Engn ETS Montreal PQ H3C 1K3 Canada Jadavpur Univ Dept Informat Technol Kolkata 700098 India TCG Ctr Res & Educ Sci & Technol Inst Adv Intelligence Kolkata 700091 India

To enhance the coverage and transmission reliability, repetitions adopted by Narrowband Internet of Things (NB-IoT) allow repeating transmissions several times. However, this results in a waste of radio resources when the signal strength is high. In addition, in low signal quality, the selection of a higher modulation and coding scheme (MCS) level leads to a huge packet loss in the network. Moreover, the number of physical resource blocks (PRBs) per-user needs to be chosen dynamically, such that the utilization of radio resources can be improved on per-user basis. Therefore, in NB-IoT systems, dynamic adaptation of repetitions, MCS, and radio resources, known as auto link-configuration, is crucial. Accordingly, in this paper, we propose SmartCon which is a Generative Adversarial Network (GAN)-based deep learning approach for auto link-configuration during uplink or downlink scheduling, such that the packet loss rate is significantly reduced in NB-IoT networks. For the training purpose of the GAN, we use a Multi-Armed Bandit (MAB)-based reinforcement learning mechanism that intelligently tunes its output depending on the present network condition. The performance of SmartCon is thoroughly evaluated through simulations where it is shown to significantly improve the performance of NB-IoT systems compared to baseline schemes.

关键词： NB-IoT link-configuration modulation and coding scheme repetitions physical resource block

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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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Queue-Aware Transmission Scheduling for Cooperative Wireless Communications

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第4期63卷 1149-1161页

作者： Wang, Ning Gulliver, T. Aaron Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 2Y2 Canada

Queue-aware transmission scheduling for cooperative wireless communications with sub-fading-block scheduling to better balance load and capacity in low mobility environments is investigated. The scheduling problem for joint cooperation scheduling and resource allocation is formulated as a constrained nonlinear integer optimization problem over an integer convex set based on a source buffer queueing analysis. It is shown that with queue-aware scheduling, the state transition matrix of the source buffer queue has a highly dynamic form. As a result, the objective function of the optimization problem does not have an analytic form in general. The constrained discrete Rosenbrock search algorithm, which is a gradient-free directed discrete search algorithm, is employed to solve the nonlinear integer problem. The output of the directed integer search algorithm is used for queue-aware transmission scheduling for the cooperative system. Numerical results are presented which show that, for cooperative transmission scheduling, the Rosenbrock search based queue-aware algorithm significantly outperforms the equal partitioning, random partitioning, and gradient-based algorithms under quasi-static channel assumptions. Under practical system conditions with unsaturated traffic, the proposed queue-aware scheduling scheme achieves the true optima, and maintains a large stability region for the buffer queue, over a wide range of channel and traffic conditions. It is also shown that when fading channel dynamics are taken into consideration, the performance of the proposed queue-aware scheduling algorithm significantly outperforms fixed relaying and fixed direct transmission channel-aware scheduling strategies.

关键词： Cooperative communications discrete search modulation and coding scheme nonlinear integer programming QoS provisioning queue-aware scheduling sub-fading-block scheduling

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Deep Reinforcement Learning Based Link Adaptation Technique for LTE/NR Systems

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2023年第6期72卷 7364-7379页

作者： Ye, Xiaowen Yu, Yiding Fu, Liqun Xiamen Univ Sch Informat Xiamen Peoples R China Xiamen Univ Key Lab Underwater Acoust Commun & Marine Informat Minist Educ Xiamen Peoples R China Chinese Univ Hong Kong Dept Informat Engn Hong Kong Peoples R China

Outdated channel quality indicator (CQI) feedback causes severe performance degradation of traditional link adaptation (LA) techniques in long term evolution (LTE) and new radio (NR) systems. This paper puts forth a deep reinforcement learning (DRL) based link adaptation (LA) technique, referred to as deep reinforcement learning link adaptation (DRLLA), to select efficient modulation and coding scheme (MCS) in the presence of the outdated CQI feedback. The goal of DRLLA is to maximize the link throughput while achieving a low block error rate (BLER). We first give explicit definitions of state, action, and reward in DRL paradigms, thereby realizing DRLLA. Then, to trade off the throughput against the BLER, we further develop a new experience replay mechanism called classified experience replay (CER) as the underpinning technique in DRLLA. In CER, experiences are separated into two buckets, one for successful experiences and the other for failed experiences, and then a fixed proportion from each is sampled to replay. The essence of CER is to obtain different trade-offs via adjusting the proportion among different training experiences. Furthermore, to reduce the signaling overhead and the system reconfiguration cost caused by frequent MCS switching, we propose a new action selection strategy termed as switching controlled e-greedy (SC -e-greedy) for DRLLA. Simulation results demonstrate that compared with the state-of-the-art OLLA, LTSLA, and DRLLA with other experience replay mechanisms, DRLLA with CER can achieve higher throughput and lower BLER in various time-varying scenarios, and be more robust to different CQI feedback delays and CQI reporting periods. Furthermore, with the SC -e-greedy policy, DRLLA can capture better trade-offs between the link transmission quality and the MCS switching overhead compared with other baselines.

关键词： Link adaptation deep reinforcement learning channel quality indicator modulation and coding scheme

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Service Quality of the Urban Microcellular Scenario in the Sub-6 GHz Frequency Bands

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IEEE ACCESS 2024年 12卷 70318-70333页

作者： Paulo, Rui R. Teixeira, Emanuel B. Velez, Fernando J. Inst Telecomunicacoes P-6201001 Covilha Portugal Univ Beira Interior Fac Engn Dept Engn Eletromecan DEM P-6201001 Covilha Portugal

This paper compares the service quality between 4G and 5G New Radio (NR) among different sub-6 GHz frequency bands in an urban micro-cellular outdoor setting. An updated version of LTE-Sim is considered to obtain the exponential effective signal-to-interference-plus-noise ratio in 4G while determining the modulation and coding scheme. System capacity is obtained by considering a video application at 3.1 Mb/s and the proportional fair (PF) scheduler while comparing 4G and 5G NR through system-level simulations (the 5G-air-simulator is considered for 5G NR). The modified largest weighted delay first (M-LWDF) scheduler is compared with the PF, though only in 4G. Optimal system performance is reached both in 4G and 5G NR for cell radii longer than two times the breakpoint distance (or beyond), which are preferable compared to the shortest values for the cell radius. We have learned that the packet loss ratio (PLR) is higher for the cell radii, R, shorter than breakpoint distance, d(BP)'. For d(BP)' <= R <= 1000 m, the PLR first decreases and then increases. For a target PLR < 2%, in 4G, the highest maximum average goodput is obtained with the M-LWDF scheduler (10-25% increase). This maximum occurs at the 2.6 GHz and 3.5 GHz frequency bands for 300 <= R <= 500 m, while at 5.62 GHz the highest goodput occurs for the longest Rs. With 5G NR and the PF, the maximum average goodput increases, in our simulations, from approximate to 14.1 (in 4G) to 26.1 Mb/s (20 MHz bandwidth).

关键词： 5G-air-simulator exponential effective SINR mapping ITU-R M.2135-1 LTE-Sim modulation and coding scheme small cell networks sub-6 GHz frequency bands two-slope model urban micro cell scenario

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DQN-Based Adaptive MCS and SDM for 5G Massive MIMO-OFDM Downlink

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IEEE COMMUNICATIONS LETTERS 2023年第1期27卷 185-189页

作者： Liao, Yong Yang, Zhijing Yin, Zisong Shen, Xuanfan Chongqing Univ Sch Microelect & Commun Engn Chongqing 400044 Peoples R China

In this letter, we propose a deep Q-network (DQN)-based joint adaptive scheduling algorithm of modulation and coding scheme (MCS) and space division multiplexing (SDM) in 5G massive MIMO-OFDM, that enables the next-generation NodeB (gNB) to choose optimal MCS and SDM for downlink scheduling that maximizes the spectral efficiency (SE) and throughput while in a low block error rate (BLER). The simulation results show that in the typical high-speed mobile and uplink interference scenarios, the proposed DQN-based algorithm has a 10% to 40% improvement in SE and a 10% to 20% improvement in throughput compared to representative algorithms, and can effectively compensate for the channel state information (CSI) feedback delay.

关键词： Downlink Throughput Interference Encoding 5G mobile communication Signal to noise ratio modulation 5G modulation and coding scheme space division multiplexing massive MIMO-OFDM deep Q-network

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Initial Parameters Selection for Serving Uplink URLLC Traffic of High-Mobility Users

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JOURNAL OF COMMUNICATIONS TECHNOLOGY AND ELECTRONICS 2023年第12期68卷 1515-1522页

作者： Shashin, A. E. Krasilov, A. N. Khorov, E. M. HSE Univ Moscow 101000 Russia Russian Acad Sci Inst Informat Transmiss Problems Moscow 127051 Russia

5G cellular systems provide a new service called Ultra-Reliable Low-Latency Communications (URLLC). In many URLLC scenarios (e.g., intelligent transport systems), users move at high speed and transmit data in the uplink. The base station shall assign transmission parameters that satisfy the strict quality of service requirements of URLLC applications and consume the least amount of channel resources. At high speed, users often change the serving base station. In this case, the task of selecting transmission parameters is complicated by the fact that the base station does not have channel quality measurements for the new user. This paper proposes various methods for selecting the initial transmission parameters when user connects to the base station. Using simulations, the paper compares various methods for different user speeds. Recommendations are given on the selection of initial parameters that provide a low amount of consumed channel resources.

关键词： cellular systems 5G URLLC uplink modulation and coding scheme high mobility

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Cross-layer channel selection and reward-based power allocation for increasing system capacity and reward in multiple-input-multiple-output wireless communications

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IET COMMUNICATIONS 2013年第10期7卷 1032-1041页

作者： Chang, Ben-Jye Liang, Ying-Hsin Tsai, Tzung-Shiun Natl Yunlin Univ Sci & Technol Dept Comp Sci & Informat Engn Taipei Taiwan Nan Kai Univ Technol Dept Multimedia Animat & Applicat Caotun Township Nantou Taiwan Chaoyang Univ Technol Dept Comp Sci & Informat Engn Taichung Taiwan

For increasing network bandwidth and guaranteeing quality of service in WiMAX, IEEE 802.16 m proposes the multiple-input-multiple-output (MIMO) technique that offers compatible specifications with the existing IEEE 802.16 family specifications. However, the performance of the IEEE 802.16 MIMO specification is significantly degraded in the high-mobility environment and high communication interference. As a result, a sender easily uses inaccurate modulation and coding scheme (MCS) and improper power allocation for different-priority users having different received signal-to-noise ratios. The system capacity is thus affected significantly. Additionally, the multiuser MIMO systems seldom consider that different-priority users and different-class traffic bring different rewards to the system. This study thus proposes a cross-layer reward-based approach (namely CLR) that consists of three schemes: adaptive modulation and coding determination, cross-layer dynamic channel selection, and reward-based weighting power allocation. The proposed CLR approach achieves accurate channel state information determination, optimal channel selection, and adaptive reward power allocation. Numerical results demonstrate that the proposed approach significantly outperforms the other approaches in system reward, system capacity, and the accuracy of the MCS determination.

关键词： adaptive modulation channel capacity MIMO communication modulation coding quality of service radiofrequency interference telecommunication traffic WiMax wireless channels cross-layer channel selection reward-based power allocation system capacity multiple-input-multiple-output wireless communications network bandwidth quality of service WiMAX IEEE 802.16 MIMO specification high-mobility environment high communication interference modulation and coding scheme MCS different-priority users received signal-to-noise ratios different-class traffic cross-layer reward-based approach adaptive modulation coding determination cross-layer dynamic channel selection reward-based weighting power allocation CLR approach channel state information determination optimal channel selection adaptive reward power allocation system capacity MCS determination

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