Carrier Aggregation Based Resource Allocation Optimization In Multi-Carrier System

The Long Term Evolution (LTE) systems are currently deployed with a maximum bandwidth of20MHz. It has significant improvements over the previous generation systems e.g. High Speed Packet Access (HSPA). It can provide a peak data rate over100Mbps in the downlink and50Mbps in the uplink. To further improve the system performance and meet IMT-Advanced, the3rd Generation Partnership Project (3GPP) has set the new study item of LTE-Advanced(LTE-A). With LTE-A, a wider bandwidth than the20MHz of the current LTE Rel’8systems will be supported, going up to100MHz.3GPP proposed to aggregate multiple carriers to form the bandwidth of the LTE-A system, which can be considered as a multi-carrier LTE R8extension, and these aggregated LTE R8carriers are referred to as component carrier. In the multi-carrier LTE-A system, LTE-A terminals can transmit data on more than one component carriers, while LTE R8terminals can only select and use one of them.Carrier aggregation technology is an effective bandwidth expansion mode, which allows the transmission of multi-carrier resource to the user terminals simultaneouslly. The component carriers can have different bandwidth, and may be distributed in different or same frequency band, while meeting the requirements of maxmum transmission bandwidth of LTE-A. The application flexibility is also ensured. In order to achieve the flexible transmission bandwidth expansion mode, carrier aggregation scenarios of LTE-A include single-band continuous carrier aggregation, single-band non-contiguous carrier aggregation and multi-band discontinuous carrier aggregation.In the thesis, it makes a brief introduction of carrier aggregation system in several aspects including the standardization organizations, the standardization processes, network structures, interfaces and so on. Moreover, the optimization of wireless resource allocation in multi-carrier system, as well as a few major questions that need to be addressed is investigated. With the assumption of multi-band non-contiguous carrier aggregation, it studies the impact of carrier scheduling scheme on the resource utilization performance of the system, and the classic independent carrier scheduling scheme is improved in two aspects of user allocation criteria and carrier collaboration solutions repectively. Finally, two classic packet scheduling schemes in multi-carrier system is discussed in, including the independent carrier scheduling and cross-carrier scheduling. The main research focuses on the component carrier and resource block joint allocation problem, and also consideres a very important factor, the backward compatibility. Namely, there exist users with different carrier access capability in the multi-carrier system. The simulation results indicate that this scheme achieves better fairness of the two user groups compared with PF scheduling, while ensuring the cell throughput.