Researches On Power Allocation And Power Control In LTE-A

The Wireless communication technology is a vital way to facilitate the peoples'life, and fulfil the peoples'requirement of communicating at any time and any place. The wireless communication technology has gone through rapid development. In resent years, a lot of novel technology and algorithms were proposed in a large numbers of documents and technical thesises to handle limited Wireless resources and increasing the throughput of system. With the 4-th generation of wireless communication technology developed and several of fresh services and demands explosive growth,3GPP proposed 3GPP LTE system, to meet the wireless communication technology. The LTE system adopted several new technologies, such as Orthogonal Frequency Division Multiplexing (OFDM), Multi-antenna technology, HARQ, Inter-Cell Interference Cancellation, Wireless Resource Scheduling, to solve the low utilization of existing spectrum, network robustness in previous wireless communication system. On the other hand, Radio Resource Management are also presents new challenges and higher demand than previous wireless communication system. In order to meet the repuirements of 4G system,3GPP introduces several new features, eg. Carrier Aggregation, Coordination Multi-Point transmission, Relay and so on, and the LTE-A system standardization work is going on.Based on Carrier Aggregation and Coordinating Multi-Point transmission and other new features of Radio Resourse management, this paper studies the downlink power allocation and uplink power control problem, involving the Carrier Aggregation, the Inter-Cell Interference Cancellation under the environment of Coordinationg Multi-Point Transmission, the Power allocation algorithm between sub-carriers, the convex optimization theory in LTE-A power control Algorithm with carrier Aggregation envirement, and the power reallocation algorithm when total power exceeds the maximum UE's power. The standardization of LTE-A is in a critical stage, the stadardization of Radio Resource Management is an important research topic, and research institutions in this field continue to publish their technical proposals and related papers.Under the guidance of information theory and convex optimization theory, we studied the power allocation and control problem in the environment of LTE-A features. And obtain some imoprtant results, which will significatlly assists the standardization of LTE-A system and practical apprication. The main results of this paper are as follows:1)Based on Carrier Aggregation and Coordination Multi-Point transmission,a system-level model with Orthogonal Frequency Division Multi-Access, adaptive Modulation and Coding, HARQ, channel information based scheduling was studied, and with the aggregation of multi carriers, how to allocate the power of eNBs in the coordination set, to improve the system throughput. With theoretical analysis and simulation results, the performation of proposed algorithm is much better than others'proposed before.2) Based on the feature of Carrier Aggregation, a system-level model with Orthogonal Frequency Division Multi-Access, adaptive Modulation and Coding, HARQ, channel information based scheduling was developed, and the theory of uplink power control and signalling was studied. Firstly, we introduced the concept of convex optimization theory, the theory of covex optimization based K-T theory, which laied a solid theoretical foundation of subsequent algorithms. Secendly, we established the model of system throughput under Carrier Aggregation environment, and demonstrates the reason why convex optimization theory and K-T theory can be applyed to this model. By controlling the transmission power of each carier, we can maximum the throughput of the whole system. With theoretical analysis and simulation results, the performation of proposed algorithm is much better than others'proposed before.3) Under the envirement of Carrier aggregation, Considering the problem which the total power of all the carriers'exceeds the maximum UE transmit power, we established the model of this problem based on the theory of Convex, and proved that this is a Log-convex problem, and can get the lobal optimal solution. Then, with the Lagrangian formula, the original problem was simplifed into the form which can be derivated. With theoretical analysis and simulation results, the performation of proposed algorithm is much better than others'proposed before.