Delav And Backlog Analvsis Of Delay-Sensitive Services In Wireless Communication System

The sixth generation mobile communication technology(6G)aims to improve reliability,reduce latency,and increase the number of connections to support large-scale real-time applications such as remote healthcare and real-time communication.The increase in packet loss can result in data loss and increased transmission delay,so studying delay and backlog helps optimize the performance of delay-sensitive services and provide reliable Quality of Service(QoS).Current research does not consider the problem of multiple complex roots in mixed-Erlang arrivals.Therefore,this thesis conducts research on delay and backlog distribution in wireless communication systems and optimizes power allocation strategies to achieve a green communication network that meets delay requirements.The main contributions are as follows:Aiming at the problem of backlog distribution in the wireless communication systems with mixed-Erlang arrivals,a method is proposed to accurately estimate the backlog distribution based on an effective capacity model with multiple complex roots.At first,the method proves the existence of multiple complex roots and solves the probability distribution function through iterative methods and the edge probability matrix.The accuracy of the method is verified through simulations.Aiming at the problem of delay distribution in the wireless communication system with mixed-Erlang arrivals,a method is proposed to accurately estimate the delay distribution based on matrix-geometric solution.By proving that the delay of communication system is statistically equivalent to the backlog of the queuing system,the backlog distribution with mixed-Erlang arrivals is derived based on the matrix-geometric solution,then the delay distribution is solved.The accuracy of the method is verified through simulations and statistical comparisons.Aiming at the power allocation problem of optimizing energy efficiency under delay constraint,an optimal power allocation scheme which can be applied to any flow model is proposed to maximize the system energy efficiency.Firstly,a method is proposed to calculate the average delay under multiple roots based on queuing theory.Secondly,considering the relationship between constant circuit power,transmission power,and data arrival rate,an optimal transmitting power allocation scheme is proposed to maximize energy efficiency under delay constraints.The accuracy of the proposed scheme is verified through simulations.To sum up,the thesis is mainly based on the effective capacity model and the matrix-geometric solution to accurately estimate the backlog and delay of the wireless communication system with Mixed-Erlang arrivals.On this basis,an optimal power allocation scheme under delay constraints is proposed to maximize the system energy efficiency,and corresponding simulation verification is given.