Research On Power Allocation With Statistical Delay-QoS Provisioning In Point-to-point Full Duplex Systems

Energy crisis and the greenhouse effect have become global problems to be solved urgently. With the rapid growth of the demand for communication services, the energy consumption of information and communication technology(ICT) has increased dramatically. It is reported that the annual ICT industry contributes to the global greenhouse gas emissions of 2%-3%, and this proportion is increasing. Meanwhile, with the development of mobile Internet and the Internet of things, the demand for communication services is transformed from a single voice service to a complex hybrid business, which leads to the increasing demand for the quality of service(QoS). For the delay sensitive service, delay-QoS is a more important performance index. How to utilize the limited spectrum resources to carry the services with different QoS requirements and to provide QoS support for heterogeneous services and improve energy efficiency is one of the core issues of the next generation wireless communication technology. However, due to the time-varying fading characteristics of the wireless channel, it is difficult to guarantee the deterministic delay of the traffic flow. QoS provisioning of statistical delay based on effective capacity theory is concerned.Full duplex communication technology is an effective way to improve the spectrum efficiency of the fifth generation mobile communication network. In order to provide users with fast, high-quality service, how to improve energy efficiency and ensure the service quality requirements of the service delay is particularly important for full duplex communication mode. Therefore, based on the statistical delay-QoS provisioning, this paper studies the energy efficiency optimal power allocation problem in point to point full duplex system, and further studies the tradeoff between energy efficiency and the effective capacity. The specific research contents are as follows.(1) In this paper, we study the optimal power allocation problem for energy efficiency over half duplex communication system. The energy efficiency of the system is expressed as the ratio of the effective capacity of the system to the total energy consumption. First without considering the average transmission power constraints, this paper studies the solution of the energy efficiency optimization model with delay-QoS constraint, and explores the effect of circuit loss power on the optimal power allocation. Secondly, considering the average transmission power constraint conditions, this paper converts the energy efficiency maximization problem into the problem of effective capacity maximization, and then explores the impact of the maximum average transmission power for power distribution.(2) The power allocation problem of energy efficiency optimization over point to point full duplex system is investigated. By introducing the self interference cancellation coefficient, this paper establishes delay-QoS constrained point-to-point full duplex system model of energy efficiency maximization problem, and proves that the objective function is quasi convex function. Without considering the average transmission power constraint conditions, this paper solves the quasi convex problem based on the affine transform and fractional programming, then obtains the optimal power allocation, and constructs the average transmission power threshold. Considering the average transmission power constraint, based on the average transmission power threshold, the problem of energy efficiency maximization is transformed into the problem of effective capacity maximization, and then the optimal power allocation is solved.(3) The tradeoff between energy efficiency(EE) and effective capacity(EC) of point to point full duplex system is studied. A multi-objective optimization problem to jointly maximize energy efficiency and effective capacity is formulated. By introducing importance weight into the problem, we can flexibly change the priority level of EE and EC, and convert the MOP into a single-objective optimization problem, which can be solved using fractional programming. For a given importance weight and a target delay-outage probability, the optimum average transmission power level is found. Then, the optimal power allocation strategy is derived based on the obtained average input power level.In summary, based on the effective capacity theory, statistical delay-QoS provisioning, convex optimization theory and information theory, we creatively study the power allocation problem of energy efficiency and the tradeoff between energy efficiency and effective capacity over point to point full duplex system with statistical delay-QoS constraint. The results can provide theoretical guidance to build a full duplex communication system with high quality of service and high energy efficiency for the next generation wireless communication technology.