DESIGN OF M2M COMMUNICATIONS OVER CELLULAR NETWORKS WITH LOCALIZATION-ASSISTED POWER CONTROL AND COMMUNICATION MODE SELECTION MECHANISM

Abstract

The location information of an unknown machine (UM) is crucial in machine-to-machine (M2M) communications for several perspectives, such as energy efficiency (EE) and spectrum efficiency (SE). Integration of location information of UMs in designing power control and communication mode selection is the key feature of this thesis. A time difference of arrival (TDOA) using weighted least square (WLS) algorithm based localization architecture for M2M communications over cellular networks is proposed. A location-aware resource blocks (RBs) allocation policy and communication mode selection mechanism for M2M communication is proposed. The system performance improves if the mode selection mechanism can be applied before transferring data which results in enhancement of throughput and reduces traffic burden. Later, a location-aware communication mode selection based power control mechanism for reducing interference in M2M communications is extended. Resource allocation between the M2M user equipment (MUE) and cellular user equipment (CUE) that share the channels in both orthogonal and non-orthogonal ways are analyzed for different modes. A water filling algorithm and Lagrange decomposition scheme based power optimization process is adopted in the proposed mechanism. Therefore, the proposed mechanism allocates the proper optimal transmit power for each UE. A MATLAB based simulation platform is developed for thoroughly investigating the performance of the localization architecture and proposed mechanisms. Performance of the proposed architecture and mechanism are evaluated in terms of root mean square error (RMSE), channel utilization, per-user throughput and per-user EE. Simulation results show that the randomly distributed AMs provide better localization accuracy compared with AMs placed in a fixed pattern. A comparison and feasibility study of the proposed mode selection scheme is also presented demonstrating better performance compared to the direct mode and indirect mode. Our investigation using the direct mode communication reduces the traffic burden on the cellular BSs compared to the other modes. Besides, the orthogonal resource sharing scheme based proposed mechanism achieves superior system performance compared to the non-orthogonal resource sharing scheme based proposed mechanism. This also suggests that localization assisted communication mode selection and power control mechanism might be a better choice for M2M communications, which is crucial for future cellular networks.