Research On Radio Resource Management For Energy Efficiency In M2M Communication For 5G Systems

More and more Human-to-Human(H2H)communication is replacing by Machine-to-Machine(M2M)communication these days.The explosive growth of the Machine Type Communication Device(MTCD)has aggravated the crowded situation of expensive licensed spectrum resources,therefore,exploring the use of unlicensed bands is one of the most effective means of alleviating the shortage situation of spectrum resources.In addition,the coexistence of a large number of H2H and M2M devices in wireless communication will inevitably lead to a large consumption of energy resources.To promote the concept of green communications,optimizing the energy efficiency of the network is benificial for sustainable development.In this paper,we mainly studied in the following three aspects for MTCD which can access two networks,including feasibility study on coexistence between LTE-U(LTE in Unlicensed Spectrum)and Wi-Fi in unlicensed band,research on energy-efficient radio resource allocation in M2M communication,and research on Discontinuous Reception(DRX)energy saving mechanism for M2M communication.The main contents and innovations are as follows.Fisrt of all,the coexistence of LTE-U and Wi-Fi on 5GHz unlicensed band is briefly described.The differences between the two wireless communication technologies are stated respectively,and two main mechanisms for inter-systems coexistence are outlined.Lots of experiments and data analysis validate the advantages of LTE-U deployment to unlicensed bands.Moreover,this paper presents the experiment data under the Duty Cycle method for inter-system coexistence mechanism.The results show that the two wireless technologies can coexist fairly and friendly under the effective coexistence mechanism,and the performance of inter-systems is even better than that of intra-systems of Wi-Fi.Secondly,as the 5GHz unlicensed frequency band is rich in radio resources,it is very suitable for the deployment of a large number of machine type communication devices.Therefore,this paper deploys M2M traffic to the unlicensed spectrum with richer and less expensive radio resources.In this paper,under the coexistence mechanism of Duty Cycle,a reasonable mathematical model is established to maximize the energy efficiency of the whole network.In addition,according to the M2M communication characters of the various types of communication equipment,the variety of QoS requirement and the insensitive delay,this paper takes the maximum delay and minimum rate of a single user as the constraint condition,a two-layer iterative algorithm is used to obtain a reasonable optimal frequency and power allocation scheme,which achieves the optimal overall network energy efficiency.Finally,the operation mechanism of the single MTCD is studied from the point of energy saving.According to some devices' characteritics of fixed cycle to access network and high tolerance for delay,the traditional DRX mechanism in LTE is improved in this paper to match the duration of multiple types of MTCD by setting several DRX cycle duration group.The MTCDs are grouped by setting the "Return Identifier".Moreover,this paper adopts idle DRX mechanism to minimize the energy consumption of the equipment to the utmost extent.The proposed improvements achieved a better energy saving effect in machine type communication.The accuracy of the theoretical research is verified by Matlab simulations at last.