Research On Resource Allocation Of 5G Internet Of Things Preamble Based On Hybrid Scheduling

Future wireless communication networks can meet the requirements of information to be acquired at any time on any device.In the near future,the Internet of Things will become a very important part of our lives.The main feature of the IoT application scenario is the large number of connected devices and small data packets.In order to meet the growing demand for IoT applications,the network should achieve high access ability and low latency.Starting from the characteristics of the Internet of Things,this paper studies the system performance and resource allocation scheme under the Internet of Things random access scenario.The main work is as follows:Firstly,under high load conditions,in order to reduce the probability of collisions when resource requests occur,3GPP proposes an Access Class Barring(ACB).Based on the existing dynamic ACB scheme,this thesis proposes an ACB control scheme based on resource reservation,which reserves user resources for the original uplink resources and for the users failed in the first access procedure completing the "secondary access" in the unit access period,thus improving the system connection performence.We compare the scheme's performance with existing dynamic ACB schemes.The simulation result shows that the scheme can increase the number of devices connected in the unit access period.The simulation result shows that the scheme can increase the number of devices connected in the unit access period,which is 14.5%.Based on the existing hybrid scheduling ACB control scheme,the resource proportional control factor is introduced,and the relationship between system access capacity and resource scale factor is demonstrated from both theory and simulation.Secondly,this thesis proposes a scheme of classifying random access preambles.Under the condition that the total number of preambles is fixed,a reasonable allocation of preambles for different devices is implemented to improve the access capacity and access delay performance of the system.The fourth chapter proves the improvement of system performance by the preamble classification scheme from both theoretical derivation and simulation.The scheme improves the access capacity by 60%compared to the preamble unclassified scheme under the condition of two kinds of arriving flow devices trying access procedure at the same time,and reduces the access delay of a class of devices by 14%.