基于混合多址的物与物通信资源分配技术研究

With the rapid development of Internet of Things (IOT) and smart user equipment (UE), the number of terminals connected to the network grows sharply. The traditional cellular network faces the challenge of massive machine-to-machine (M2M) connections. In order to improve the access capacity, from multiple access and resource allocation points of view, this project will research the capacity of access, hybrid multiple access technology and corresponding resource allocation algorithms. The purpose of this research is to maximize the number of accesses within limited time-frequency resources. To do so, this project will first derive the expression of system capacity for orthogonal multiple access, non-orthogonal multiple access and hybrid multiple access. Secondly, this project will study the interference cancellation technology for non-orthogonal multiple access and research the switching threshold for different types of access. Based on these results, this project will propose a hybrid multiple access scheme to improve the number of accesses in a unit of resource block. Thirdly, this project will study the relationship among the capacity of hybrid multiple access, resource allocation, system load and multiplexing factor. With the principle of maximum capacity, this project will propose the algorithms of load prediction, resource allocation scheme for different type of access modes and resource allocation scheme for different channels. The project will produce new multiple access technology and resource allocation algorithms, and these achievements will contribute not only to the fundamental theoretical of IOT, but also to the development of the fifth generation (5G) of mobile technology.

随着物联网和智能终端的快速发展，物与物(M2M)通信的终端连接数迅猛增长，传统移动通信网络面临着M2M终端海量接入的挑战。为了提高系统的接入容量，本项目从多址接入和资源分配的角度出发，研究系统接入容量、混合多址接入技术和资源分配算法，在有限的时频资源内使终端连接数最大。为此，本项目将首先研究面向M2M通信的正交多址、非正交多址和混合多址方式的系统接入容量,推导容量表达式；然后，研究非正交多址接收机的干扰消除技术和不同接入方式的切换门限，提出混合多址接入方案，提高单位资源的终端接入数量；最后，研究混合多址的接入容量与资源分配、系统负载、复用因子之间的关系，以最大化系统接入容量为设计准则，设计负载预测方案、多址接入资源分配方案和信道资源分配方案。本项目研究将产生新的终端多址接入技术和资源分配算法，不仅为物联网的应用提供理论基础，也为第五代（5G）移动通信技术的发展贡献力。

物与物通信的特点是终端数量众多，传输的数据包较小且以上行传输为主，这就需要5G网络要在有限的上行资源内接入更多终端。提高网络接入容量主要从提高单位资源终端接入数量以及提高有效资源利用率两个方面考虑。为了提高单位资源终端接入数量，我们研究了非正交多址接入技术，将非正交多址技术用于终端上行接入和数据传输。在此基础上，我们确定了正交多址接入与非正交多址接入的SNR门限，以及非正交多址不同系统负载下的切换门限，并设计了基于SNR门限选择的混合多址接入技术，该技术可以使网络接入容量提升70%。为了提高资源利用效率，我们提出了新的随机接入信道映射方法，在随机接入信道上增加UE ID信息的映射，减小了因为用户碰撞带来的资源浪费。此外，我们还研究了混合多址资源分配优化，在容量最大化准则分配正交多址与非正交多址资源、以及接入随机信道和数据传输信道之间的资源，使得资源效率得到进一步提高。经过仿真，结合混合多址接入技术、新型随机接入信道资源分配算法，网络接入容量比传统的正交接入容量提升了3倍。