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.
