未来蜂窝网络中资源受限条件下大规模MTC设备接入机制

To cope with the challenges introduced by connection ubiquity and data quantity of massive machine type communications (mMTC) to resource-constrained wireless systems, this project adopts the strategy of clustering access to enable future cellular networks to carry mMTC services effectively, starting from analyzing the necessary conditions for access and the main links causing access failures...Firstly, for the challenges of poor narrow beam coverage of massive antennas and limited pilot resources, a continuous omnidirectional precoding scheme with low pilot overhead is proposed, enabling base stations (BS) with massive antennas to effectively broadcast public information, which provide widely distributed MTC devices with the necessary information for random access. Secondly, aiming at the challenges brought by limited equipment energy, transmission capacity, and complex interference, an energy-efficient cluster planning scheme in complex interference environment is proposed. Under the constraints of MTC communication requirements and equipment service capabilities, network energy efficiency is improved by clustering. In addition, for the contradiction between the limited number of random access sequences and the large number of devices, a stable group paging access scheme based on optimal traffic scattering is proposed to improve the access success probability. ..By breaking through the above key technologies, this project can provide an access solution for massive MTC devices, which enables future cellular networks to effectively carry mMTC services and meet the urgent requirements of low power consumption and large connections.

为应对大规模MTC连接泛在化、数据海量化对资源受限无线系统带来的挑战，本课题针对未来蜂窝网络有效承载大规模MTC业务这一问题，采用海量设备分簇接入的策略，从接入的必备条件和接入失败的主要环节入手展开研究。.首先针对大规模天线窄细波束覆盖性能差及导频资源受限等挑战，提出低导频开销的连续全向预编码方案，使配置大规模天线的基站可实现公共信息的有效广播，为广泛分布的MTC设备提供接入的必需信息。其次针对设备能量、传输能力受限以及复杂干扰带来的挑战，提出复杂干扰环境下高能效簇规划方案，在满足MTC通信需求和设备服务能力约束下，确定分簇个数、提升网络能量效率。此外，针对随机接入序列有限与设备数目众多这一矛盾，提出基于最佳流量分散的稳定组寻呼接入方案，以提高接入成功率。.通过突破上述关键技术，本课题可提供大规模MTC设备接入方案，利用未来蜂窝网络有效承MTC业务，并满足其低功耗、大连接的迫切需求。

针对机器类型通信对于低功耗、大连接的迫切需求，同时考虑到未来蜂窝网络中大规模天线广泛部署和灵活频谱使用策略等条件，本课题针对未来蜂窝网络中资源受限条件下大规模机器类型通信（machine type communication, MTC）设备接入方案展开研究。本课题从随机接入的必备条件和造成随机接入失败的关键环节入手，重点研究面向大规模天线的下行公共信息广播机制、复杂干扰环境下大规模MTC设备簇规划及MTC簇头高效接入机制。针对上述内容，本课题采用基于空时编码的全向传输来实现大规模天线基站的下行公共信息广播，所设计的连续全向预编码可在有限时隙内实现全部角度上等功率接收，具有更好的覆盖性能，且可实现满分集增益。其次，为提高大规模MTC网络的频谱资源利用率和网络生存时间，本课题在簇间资源复用场景下设计了最小化网络功率消耗的大规模MTC 簇数目规划方法；在此基础上，进一步提出了延长网络生存时间的簇头选择及功率控制方法，减小网络信令开销、降低MTC设备能量消耗。此外，针对现有组寻呼接入中单个寻呼组内大量设备接入时组内拥塞问题，本课题提出一种基于最佳流量分散的稳定组寻呼接入方案，该方案可以保证设备数目变化不会影响接入成功率，而且资源利用率始终保持较高水平。通过本课题技术攻关，可实现利用蜂窝网络有效承载大规模MTC业务，使得海量MTC设备可通过蜂窝网络实现接入和数据上传，为推进物联网发展应用提供了必要的理论支撑。