The Study Of Relaying In Lte-Advanced Systems

With the rapid development of wireless communication technology, the number of users, types of mobile service and the request of bandwidth are increasing consequently. Only3G systems can’t meet the requirement of future mobile users. Next generation cellular standards such as LTE-A (Long Term Evolution-Advanced) and IEEE (Institute of Electrical and Electronics Engineers)802.16j can be poised to satisfy the demand of IMT-A (International Mobile Telecommunication-Advanced). These systems can achieve a peak date rates of100Mbps and1Gbps in the environments of high mobility and pedestrian, respectively. As a result, higher speed mobile broadband access can be provided. As one of the key technologies of LTE-A, relaying has drawn more and more attentions due to its advantages in improving throughput and increasing coverage. When relaying terminals are deployed in system, the costs of additional power and bandwidth incurs by them. In order to make better use of system resources, we must design new resource allocation algorithms to minimize system power or maximize throughput.This dissertation is focused on the thesis of time and frequency resource allocation based on the time division dulplexing relaying systems. Detailed analysis of optimizing system power and throughput is done. The main contribution of this dissertation is as follows:1、The analysis of power optimization in time division dulplexing relaying systemBased on the system of downlink time division dulplexing relaying, the power optimization problems in the context of single user is formulated combining with time slots, power, bandwidth rate constraints. By converting the system model and detailed theoretical analysis, the optimal resource allocation algorithm under this scenario is derived.2、The analysis of throughput optimization in time division dulplexing relaying systemBased on the system of downlink time division dulplexing relaying, the throughput optimization problems in the context of single user is formulated combining with time slots, power, bandwidth rate constraints. By converting the system model and detailed theoretical analysis, the optimal resource allocation algorithm under this scenario is derived.Second, based on the above system model, the optimal problem of maximizing throughput is also formulated in the context of multi users. With analysis and several assumptions, the algorithm of resource allocation to maximizing the system throughput is presented.The dissertation also considerers the scenario of adding the service of M-UE during the second slot, the optimal problem of maximizing system throughput under this scenario is formulated and analyzed, and then the optimal resource allocation algorithm is proposed.Simulation results under these scenarios are given and show that these proposed resource allocation algorithms outperform the traditional schemes significantly.