A Novel Random Access for Fixed-Location Machine-to-Machine Communications in OFDMA Based Systems
A Novel Random Access for Fixed-Location Machine-to-Machine Communications in OFDMA Based Systems
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DOI：
10.1109/lcomm.2012.072012.120788
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发表时间：
2012-07
期刊：
影响因子：
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通讯作者：
K. Ko;Min Jeong Kim;Kuk Yeol Bae;D. Sung;J. H. Kim;J. Ahn
中科院分区：
文献类型：
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作者：
K. Ko;Min Jeong Kim;Kuk Yeol Bae;D. Sung;J. H. Kim;J. Ahn
机器对机器（M2M）通信通常具有大量设备、低数据速率、小尺寸数据包和低或无移动性等特点，而人与人（H2H）通信通常支持少量用户、高数据速率、大尺寸数据包和高移动性。为了在未来的蜂窝系统中支持M2M通信，最具挑战性的问题之一是解决由于大量设备的访问尝试而导致的随机访问中的碰撞问题。对于大型固定位置M2M业务（如智能计量和遥感），由于机器设备与其eNodeB之间的距离固定，每个机器设备都具有固定的上行时序对齐（TA）。针对未来基于正交频分多址（OFDMA）的蜂窝系统（如长期演进（LTE）系统）中大量固定位置机器设备的M2M通信，提出了一种基于固定TA信息的新型随机接入方案。与传统的随机接入方案相比，所提出的随机接入方案具有较低的碰撞概率、较短的接入延迟和较高的能效。
Machine-to-machine (M2M) communications typically exhibit features such as a large number of devices, low data-rates, small-sized packets, and low or no mobility, while human-to-human (H2H) communications typically support a small number of users, high data-rates, large-sized packets, and high mobility. To support M2M communications in future cellular systems, one of the most challenging problems is to resolve a collision problem in random access because of access attempts from a large number of devices. For a large class of fixed-location M2M services such as smart metering and remote sensing, each machine device has fixed uplink timing alignment (TA) due to a fixed distance between the machine device and its eNodeB. We propose a novel random access scheme based on its fixed TA information for M2M communications at a large number of fixed-location machine devices in future orthogonal frequency division multiple access (OFDMA)-based cellular systems like Long Term Evolution (LTE) system. The proposed random access scheme yields significantly lower collision probability, shorter access delay, and higher energy-efficiency, compared with the conventional random access scheme.