Research Of Energy Saving Scheme In A Wireless Network

In recent years,with the constant evolution and development of mobile communication equipment,in-formation and communication industry took a large proportion of the global emission of carbon dioxide,and its energy consumption has increasing proportion in global energy consumption.In order to reduce envi-ronment pollution and energy consumption,energy efficiency(EE)becomes a crucial new metric applied to design future communication systems.By improving EE,energy consumption can be saved,which will contribute to the reduction of operating costs and the emission of carbon dioxide of communication.In the communication system,the energy-efficient packet transmission is a hotspot in the EE maximization research.Unlike the previous articles about the energy-efficient packet transmission,this thesis focuses on the study of the transmission time of packets in the wireless network,where circuit power is considered.By adjusting each packet's transmission time,the energy consumption of the whole system can be minimized.First,this paper develops a novel approach to obtain energy-efficient transmission schedule with non-ideal circuit power over wireless networks involving a single transmitter and multiple receivers.Although the formulated problem is non-convex,we propose a novel algorithm called "OOSCPMR"(the optimal of-fline scheduling with non-ideal circuit power with multi-receivers)according to the special structure of the problem and find the optimal offline solutions to optimize the energy-efficient transmission policy.It is re-vealed that the packets can be divided into two types where one type of packets have been determined to be transmitted using the EE transmission time,and the other type of packets are determined by the ID moveright algorithm,which is the most energy-efficient transmission schedule with ideal circuit power.Then,we prove the optimality of the proposed algorithm.Finally,we develop an energy-efficient online schedule based on the proposed optimal offline schedule.It is shown by simulations that the performance of the online policy is very close to the proposed optimal offline schedule.Next,this paper investigates the problem of energy-efficient packet transmission with arbitrary arrival instants and deadline constraints under non-ideal circuit power consumption,which means there exists Non-FIFO(Non-First-In-First-Out)packets that arrive earlier will have a deadline that is also earlier.We show that the problem is not a convex program,but can be reformulated as a convex problem.We first investigate the necessary and sufficient conditions of the optimal offline transmission schedule.Based on these conditions,an efficient algorithm which finds the optimal transmission schedule minimizing the total energy consumption are propose.Next,we show that the proposed algorithm is optimal by proving it satisfies the sufficient conditions.In addition,based on the proposed optimal offline policy,an efficient heuristic online policy which requires only the causal knowledge of packets arrival and deadline realizations is proposed.Finally,the simulation results show the proposed algorithm can solve the energy minimization problem with the Non-FIFO packets under the non-ideal circuit power consumption.