The Research Of Joint Resource Allocation Algorithm Based On Relaying OFDMA System

The development of information technology change rapidly,people demand for communication are not limited to the common communication function,digital communication,broadband and multimedia has become the trend,high data rate,but also need high communication reliability,high frequency utilization and high coverage characteristics etc..Orthogonal frequency division multiple access(OFDMA)technology and relay technology,make people's needs to be realized,OFDMA multiple access technology is in the orthogonal frequency division multiplexing(OFDM)and on the basis of the disturbance resistant to frequency selective fading caused by dry and high-speed data transmission between codes,both at the same time the high spectral efficiency advantages,coupled with the use of relay technology,greatly improve the system coverage,but also is conducive to the expansion of system throughput.The main research object of this paper is the distribution of important technical resources in the relay OFDMA system.The first describes the significance of rational resource management of relay system and summarizes the previous research results,and then the detailed description of the main object of the article,also is the relay technology and OFDMA technology,at the same time for the relay node selection algorithm to do a comparative study.Secondly,the analysis and research of the allocation algorithm of wireless resources are included in the key category,and the single and multi user systems are analyzed and investigated.Single user system includes two power allocation algorithms: water injection algorithm and greedy algorithm.Multi-user system caters to all kinds of user requirements,including margin adaptation and rate adaptation(RA),two resource optimization principles.The most important result of this paper is on the third generation communication system algorithm was further improved,found on the basis of OFDMA relay system,resource allocation algorithm has been optimized,coupled with the use of relay technology,but also to promote the development of previous allocation algorithm.The article is divided into two major plates,that is,the problem of resource allocation and the selection of relay nodes.For relay node selection,we should first consider the key factor of base station relay and relay user's equivalent signal-to-noise ratio,and how to allocate the resources to two sub steps,which are sub carrier allocation and power allocation.In this step allocation of subcarriers,business amount in the end how much the introduction of proportional factor mainly depends on the users themselves,if the total power distribution is quantitative,in order to achieve the optimal system capacity value,the more equal distribution,can be used to maximize the system capacity and proportional fairness algorithm;after the subcarrier allocation over again the allocation of resources under the premise of fixed subcarrier allocation,power allocation standard for each user has been calculated in the previous step,then only need to follow the single user algorithm can be a reasonable allocation for each user.The survey report shows that the mentioned algorithm whether in the system capacity and the computational complexity,advantages,but because of the emergence of the scale factor,the factor will lead to repeated use in the distribution process,so that a given proportion brings a slight error,the system research of these algorithms are not applicable to the high proportion of.