Research On Resource Allocation Algorithms In TD-LTE-A System Downlink

With the information age approaching, needs for Internet services have beenmore and more complicated, which generates higher service velocity requirementsin wireless communication systems from users, promoting the development ofwireless communication system from one generation to another. Proposed by the3GPP organization, the LTE system along with the following LTE-A system hasbeen extensively studied, research results of which are advancing towardsmarketization and industrialization gradually. In2004, China puts forward theTD-LTE standard using OFDMA technology to the3GPP organization and, on thisbasis, introduces the indigenously-developed standard of TD-LTE-A. Although thephysical layer technology has been developed relatively maturely, limitedbandwidth and resource transmitting power in base station are still in severescarcity in wireless systems, for which the increasing demands for wirelesscommunication performance are difficult to meet by simply upgrading the physicallayer technology. In that case, efficient management and allocation of radioresources becomes a hot research nowadays. And downlink resource optimizationallocation in the OFDMA-adopted TD-LTE-A system is promising to improve theperformance of wireless networks.The main content of this paper is the power allocation algorithm in thedownlink resource allocation in TD-LTE-A, aimming at adapting to a variety ofservice environments in the TD-LTE-A system as well as enhancing users'satisfaction for service. This paper firstly outlines the background, purpose andsignificance of the subject. Secondly?the paper has studied and analysed thechannel gain model for TD-LTE-A system and corresponding OFDM technologyas well as the cross-layer optimization ideas, what's more, the application ofcross-layer optimization design in the TD-LTE-A system resource allocation isintroduced. Subsequently?the TD-LTE-A downlink resource allocation schedulingprocess, performance evaluation standard along with resource block allocationmethods have been studied, with the downlink power allocation algorithm inTD-LTE-A system researched intensively. Via the elaborate theory analysis oftraditional water-filling algorithm and the simple cooperative power allocationalgorithm, the shortcomings of both algorithms are summarized and a jointoptimization design based genetic algorithm is thus proposed as the solution forpower allocation problem therein. Finally, condisering the actual applicationscenarios, both the simple cooperative power allocation algorithm and geneticalgorithm are simulated. Based on theoretical and simulation results, the paper proceeds analyses ofsimple cooperative power allocation algorithm and genetic algorithm in detailrespectively, results of performances with regard to three aspects including theuser service QoS guarantee in system, BE customer service and overall userservice in system obtained. By comparing the performance of two algorithms wecan conclude that, as the number of QoS users increases, the genetic algorithmowns advantage in getting performance improved contrasting the simplecooperative power allocation algorithm.