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Radio-aware resource allocation architecture for QoS differentiation in WiMAX networks

WIRELESS NETWORKS 2015年第8期21卷 2711-2726页

作者： Pizzi, Sara Molinaro, Antonella Araniti, Giuseppe Univ Mediterranea Reggio Calabria Reggio Di Calabria Italy

One of the keys to the success of WiMAX is its capability of supporting traffic with heterogeneous quality of service (QoS) requirements. The current standard specifies the general QoS architecture for WiMAX but the design of the main building blocks (e.g., connection admission control, packet schedulers) is left up to the vendors' implementation. This gap motivates the paper that aims to design and analyse a channel-aware QoS framework for efficiently managing radio resources in a WiMAX network. The proposed architecture integrates the specifications of (1) a connection admission control module and a packet scheduler implemented at the base station (BS) to manage bandwidth requests from the subscriber stations (SSs), and (2) a scheduler at the SS that distributes the granted resources among the active data flows. Simulation results show that the proposed framework enables QoS differentiation and intra-class fairness, and demonstrate that a combined design of the BS and SS schedulers is necessary for effective QoS provisioning.

关键词： WiMAX Quality of service Scheduling Channel awareness adaptive modulation and coding

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adaptive radio resource management for maximizing reward and balancing loads in 4G hybrid universal mobile telecommunications system and long term evolution communications

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WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2015年第3期15卷 510-526页

作者： Chang, Ben-Jye Liang, Ying-Hsin Cao, Kai-Xiang Natl Yunlin Univ Sci & Technol Dept CSIE Touliu Taiwan Nan Kai Univ Technol Dept MAA Caotun Taiwan

The universal mobile telecommunications system (UMTS) and long term evolution (LTE)/LTE-advanced specifications have been proposed to offer high data rate for the forwarding link under high-mobility wireless communications. The keys include supporting multi-modes of various coding schemes (e.g., VSF-OFCDM, OFDM, OFDMA), multiple-input multiple-output, relay networks, and so on. To balance loads among different communication interfaces is one of the most important issues that should be addressed for achieving efficient radio resource allocations. In a shared packet service, the 3GPP UMTS adopts the VSF-OFCDM interface to allocate orthogonal codes of an OVSF code tree in two-dimension (2D) spreading at the time and frequency domains. However, it easily leads to high packet loss rate and high bandwidth waste rate, because it does not consider interference and the adaptive modulation and coding scheme simultaneously. Conversely, although the LTE/LTE-advanced interface offers a high data rate, it suffers from unbalanced loads and moderate reward. This paper thus proposes an adaptive radio resource allocation for balancing loads between the UMTS and LTE/LTE-advanced interfaces according to various interference and mobility environments. In addition, an adaptive multi-code allocation is proposed for the UMTS to minimize the bandwidth waste rate while guaranteeing quality of service. Numerical results indicate that the proposed approach outperforms other approaches in fractional reward loss and system utilization. Copyright (c) 2013 John Wiley & Sons, Ltd.

关键词： adaptive radio resource management adaptive modulation and coding load balancing resource block 2D-spreading multiple input multiple output multicode LTE-A

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Routing Scheme for Bandwidth Guaranteed Traffic in AMC-Enabled Wireless Mesh Networks

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2009年第10期E92D卷 1934-1944页

作者： Nishioka, Jun Yamano, Satoru NEC Corp Ltd Syst Platforms Res Labs Kawasaki Kanagawa 2118666 Japan

Backbone network of the mobile networks, i.e. mobile backhaul networks, is an important part of mobile network system. With the decreasing size of mobile network system cells, it is considered next-generation mobile backhaul networks will form mesh topology. Most mobile backhaul networks are formed with microwave radios. To increase data rate. adaptive modulation and coding (AMC) is used for wireless links. However, the data rate of each wireless link changes over time and leads to unexpected packet loss or traffic degradation. This paper proposes a routing, scheme and methods for estimating the transmission parameters or modes of wireless links to route bandwidth guaranteed flows over mobile backhaul networks. Proposed routing scheme can reduce degradation of flows caused by unexpected changes of the data rate of wireless links. We evaluate our routing scheme when mode distribution of links follows normal, uniform and Poisson distributions. This paper shows mode estimation using mode history of link to estimate the link quality can route bandwidth guaranteed flows efficiently by choosing more stable links for the path.

关键词： adaptive modulation and coding mobile backhaul routing

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Scalable Video Broadcast Over Downlink MIMO-OFDM Systems

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2013年第2期23卷 212-223页

作者： Yang, Zan Wang, Xiaodong Peking Univ State Key Lab Adv Opt Commun Syst & Networks Beijing 100871 Peoples R China Columbia Univ Dept Elect Engn New York NY 10027 USA King Abdulaziz Univ Jeddah 21413 Saudi Arabia

We propose a cross-layer design framework for efficient broadcasting scalable H. 264 videos over the downlink multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing systems. The objective is to maximize the average peak signal-to-noise ratio of the received video streams by jointly optimizing video layer extraction, subcarrier allocation, modulation and coding, and transmit precoding, considering the heterogeneity of video sources and channel conditions. Specifically, to exploit the MIMO channel, we employ a codebook-based linear transmit precoding strategy with limited feedback. Given the fact that different quality layers of the video have different importance, we propose an adaptive modulation and coding scheme, where a fixed coding rate is used for each quality layer and unequal error protection is implemented for different layers. We further propose a subcarrier allocation strategy to assign transmission channels for different layers of different users' videos, to satisfy the decoding dependence constraints among the video layers and to maximize the reconstructed video quality. The proposed scalable video broadcast solution has a low complexity and low signaling overhead, which makes it suitable for practical implementations. We provide experimental results to demonstrate the effectiveness of the proposed solution, using both model-based simulations and an end-to-end software simulation testbed.

关键词： adaptive modulation and coding auction algorithm downlink broadcast H.264 limited feedback linear precoding MIMO-OFDM scalable video subcarrier allocation

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A Flexible Resource Allocation and Scheduling Framework for Non-real-time Polling Service in IEEE 802.16 Networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第2期8卷 766-775页

作者： Hou, Fen She, James Ho, Pin-Han Shen, Xuemin (Sherman) Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

This paper proposes an efficient yet simple design framework for achieving flexible resource allocation and packet scheduling for non-real-time polling service (nrtPS) traffic in IEEE 802.16 networks. By jointly considering the selective Automatic Repeat reQuest mechanism at the media access control layer as well as the adaptive modulation and coding technique at the physical layer, the proposed framework enables a graceful tradeoff between resource utilization and packet delivery delay while maintaining the minimum throughput requirements of nrtPS applications. An analytical model is developed for parameter manipulation in the proposed framework, where some important performance metrics, such as inter-service time, delivery delay, goodput, and resource utilization, are investigated for performance evaluation. Simulation results are given to demonstrate the efficiency of the proposed framework and verify the accuracy of the analytical model.

关键词： Non-real-time polling service (nrtPS) scheduling automatic repeat request IEEE 802.16 adaptive modulation and coding

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Novel link adaptation for TETRA cellular systems

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2009年第4期22卷 483-501页

作者： Tarchi, Daniele Fantacci, Romano Tanriover, Cagri Honary, Bahram Univ Florence Dept Elect & Telecommun I-50139 Florence Italy SRT PMR Technol Ltd Basingstoke RG24 9NP Hants England Univ Lancaster Dept Commun Syst InfoLab21 Lancaster LA1 4WA England

One of the main challenges for future wireless systems is to enhance the effective data throughput by exploiting the allocated bandwidth as much as possible. Among several approaches at different layers, one of the most important is constituted by the so-called link adaptation (LA) techniques. They are characterized by the adaptation of a set of transmission parameters to the channel state in order to improve performance. In this context, this paper is focused on the analysis of a particular class of LA techniques called adaptive modulation and coding, where the modulation and coding rate of transmission can vary according to the channel behavior. In particular, a novel LA algorithm, namely the timed window (TW) method, suitable for time-division Duplex systems is proposed here. The performance of the TW algorithm is evaluated by taking actual user mobility conditions, communication channel behavior, as well as the physical layer effects into account. Finally, it is important to stress that, even if the wireless bearer considered in this study is TETRA (TErrestrial Trunked RAdio), the approach is quite general and it can be of interest for other wireless networks and can be optimized for different channel models (e.g. TU50, HT200, etc.). Copyright (C) 2008 John Wiley & Sons, Ltd.

关键词： link adaptation TETRA adaptive modulation and coding cross-layer simulation modeling

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Optimised secure transmission through untrusted AF relays using link adaptation

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INTERNATIONAL JOURNAL OF ELECTRONICS 2016年第5期103卷 831-840页

作者： Taki, Mehrdad Sadeghi, Mohammad Univ Isfahan Fac New Sci & Technol Dept Energy Esfahan Iran

A new transmission scheme is presented for a two-hop relay network including two AF relays, considering physical layer security where relays are not able to detect signal with an acceptable bit error rate (BER) but the combined received signal is detected with an acceptable BER at the final receiver. It is assumed that there is no direct path between the transmitter and the receiver (relay network without diversity). adaptive modulation and coding is utilised at the transmitter and transmission powers of the transmitter and of the relays are continuously adapted provisioning individual average power constraint for each node. Numerical evaluations show that an acceptable performance degradation is seen by the proposed secure relaying scheme compared to the optimum relay selection scheme without security constraint.

关键词： adaptive modulation and coding physical layer security Amplify and forward relay link adaptation

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adaptive Transmission in Cellular Networks: Fixed-Rate Codes With Power Control Versus Physical Layer Rateless Codes

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2019年第6期18卷 3005-3018页

作者： Rajanna, Amogh Dettmann, Carl P. Univ Bristol Sch Math Bristol BS8 1TH Avon England

adaptive transmission schemes are a crucial aspect of radio design for future wireless networks. This paper studies the performance of two classes of adaptive transmission schemes in cellular downlink. One class is based on physical layer rateless codes with constant transmit power and the other uses fixed-rate codes in conjunction with power adaptation. Using a simple stochastic geometry model for the cellular downlink, the focus is to compare the adaptivity of fixed-rate codes with power adaptation to that of physical layer rateless codes only. The performance of both the rateless and fixed-rate coded adaptive transmission schemes are compared by evaluating the typical user success probability and rate achievable with the two schemes. Based on both the theoretical analysis and simulation results, it is clearly shown that the fixed-rate codes require power control to maintain good performance, whereas the physical layer rateless codes with constant power can still provide robust performance.

关键词： adaptive modulation and coding rateless codes transmit power adaptation fixed-rate codes adaptive transmission cellular downlink and fractional power control

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Power and Discrete Rate Adaptation in Wideband NOMA in Frequency-Selective Channels

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2024年第5期23卷 4186-4198页

作者： Sruthy, S. Mehta, Neelesh B. Indian Inst Sci Dept Elect Commun Engn Bengaluru 560012 India

Power-domain non-orthogonal multiple access (NOMA) superimposes signals of multiple users and transmits them simultaneously. To be implemented in 5G and beyond orthogonal frequency division multiplexing systems, it must adhere to the constraint imposed by the standard that the same modulation and coding scheme (MCS) and power must be used across all physical resource blocks (PRBs) assigned to each user. However, the PRBs have different gains in wideband channels and the MCSs must belong to a discrete, pre-specified set. We propose a method that uses the exponential effective signal-to-noise ratio mapping (EESM) to systematically determine whether a feasible power allocation exists for a given choice of MCSs, and to find the MCSs that maximize the weighted sum rate for multiple user NOMA. We then propose a novel power-normalized EESM with backtracking (PB) method. It develops and exploits explicit analytical criteria to check for feasibility. We prove that it is a relaxation of the original problem under various conditions and is exact for narrowband channels. The average weighted sum rate of PB is indistinguishable from that of the EESM-used method despite its lower complexity. It is higher than that of wideband orthogonal multiple access, which is currently employed by 5G.

关键词： Non-orthogonal multiple access (NOMA) wideband adaptive modulation and coding power allocation exponential effective signal-to-noise ratio mapping

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How to minimize the TCP effect in a UMTS-HSDPA system?

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WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2005年第4期5卷 473-485页

作者： Assaad, M Zeghlache, D Inst Natl Telecommun F-91011 Evry France

This paper focuses on the interaction between the transmission control protocol (TCP) layer and the radio interface in a 3G wireless system. An analytical model to evaluate the impact of TCP on the UMTS-HSDPA capacity is presented. A method to minimize the effect of TCP on wireless networks using shared channels is also proposed. High speed downlink packet access (HSDPA) is an evolution of the UNITS standard over the air interface to achieve higher aggregate bit rates through the introduction of adaptive modulation and coding, hybrid automatic repeat request (ARQ), fast scheduling, fast cell selection, and multiple input multiple output (MIMO) (space time coding and blast) techniques. The proposed model is used to evaluate the effect of the TCP protocol on the bit rate of various data services (at 64 and 128 kbps). As expected, the bit rate per flow decreases strongly if the congestion frequency in the wired network increases. However, the overall capacity achieved by HSDPA is not as affected by the TCP layer. Using this result, a method to maintain the bit rate per TCP flow at a given value without loosing much cell capacity is proposed. The findings are supported by simulation results. Copyright (c) 2005 John Wiley & Sons, Ltd.

关键词： UMTS HSDPA adaptive modulation and coding HS-DSCH HARQ TCP

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