一种固定位置MTC设备的随机接入改进算法

An Improved Random Access Algorithm for Stationary MTC Devices

针对海量机器类通信(Massive Machine Type Communications,mMTC)场景下传统随机接入存在大量前导碰撞问题,提出了一种对终端侧和基站侧的接入改进算法,利用前导标记序列和固定位置随机接入终端的定时提前(Timing Advance,TA)信息,使得基站能合理地确定应该向哪些终端回复随机接入响应消息,避免碰撞终端占用资源发送消息3(Message 3,Msg3),实现前导高效利用。仿真表明,该算法在均匀分布和Beta分布接入模型下均能有效降低前导碰撞概率,提高终端的接入成功率,并且拥有合理的平均接入时延。

For the large number of preamble collisions problem in traditional random access procedure under massive machine type communications(mMTC)scenario,an improved access algorithm for terminal side and base station side is proposed,in which the preamble tag sequence and the timing advance(TA)information of the fixed-location random access terminals are used,so that the base station can reasonably determine which terminals it should reply to the random access response message,to avoid colliding terminals using resources to send Message 3(Msg3),and achieve efficient use of preamble.Simulation results show that the algorithm can effectively reduce the probability of preamble collision,improve the probability of terminal successful access,and has a reasonable average access delay under both the uniformly distributed and the Beta distributed access model.