Dynamic Resource Allocation Algorithm For OFDMA In LTE-Advanced

In the recent years, LTE has obtained a considerable development, by now morethan301telecom operators aroung the world have been investing or deploying LTEcommercial network. In order to meet the4G communication needs,3GPP furtherinitiates the LTE-A project. With the growing demands of users and the scarcity ofspectrum, wireless resource management becomes more and more important in thefuture mobile communication systems. Therefore, as the core of wireless resourcemanagement, dynamic resource allocation is the key to improve system performanceand guartanee the user QoS.This paper studies on the OFDMA dynamic resource allocation algorithm ofLTE-A system, describes the related theories, including LTE/LTE-A architecture, thekey technologies of the physical layer and the existing resource allocation algorithmsetc., analyzes two main models of dynamic resource allocation: rate adaptive problemand margin adaptive problem.For the Rate adaptive problem in multi-user OFDMA system, an optimal powerallocation algorithm is designed in the case that subcarriers have been allocated. Intradional argorithm, the optimal power allocation can be reached through a largenumber of iterations. however, the proposed algorithm can achieves the optimalsolution without iterations, and simulation experiment confirms the theoreticalanalysis.For the margin adaptive problem in MU-CoMP of LTE-A system, a real-timeresource allocation algorithm is presented, the joint optimization problem is dividedinto three steps to solve: firstly, calculates each user’s required subcarrier number basedon the rate requirements and average channel gain; secondly, allocates the specificsubcarrier according to the users’ spatial correlation degree and the channel gain;thirdly,completes the bit loading process quickly for each user using an improved fastbit loading algorithm. Simulation results show that the algorithm obtain a goodcompromise between complexity and throughput.