Resource Allocation Technology Of Full Duplex In LTE-A System Based On Power Control And Unified Priority

The increasing diversity application in network has brought about the rapid growth traffic of mobile Internet, but at the same time, it also puts forward higher requirements on the speed and bandwidth of mobile communication. How to provide better communication rate and system throughout is the core issue of communication technology in the future wireless. In recent years, Co-frequency Co-time Full Duplex(CCFD) has been proposed as an effective way to improve the spectral efficiency.The key to achieve CCFD is to solve self interference cancellation. From the current situation of research, there is a lot of improvement in the existing elimination scheme, and the effect is not very well. This paper will change the model of CCFD resource allocation, letting one user's uplink and the downlink of another user share the same resource block in the same scheduling period, so the problem can be changed from self interference to users' interference, by achieving the base station's self interference cancellation. By the path loss, the main factor of user's interference is the user's distance and the transmission power. When the user's distance is large enough or the user's transmission power is small enough, the interference between users will be very small or even negligible and the proposed algorithm in this paper is also focus on these two factors.A resource allocation algorithm of full duplex for LTE-A system based on power control is presented in this paper. At first, the algorithm uses the proportional fairness algorithm for downlink resource allocation, then choose user for each resource block by three small steps in turn. The algorithm calculates the optimal transmit power for each user in the current resource block firstly. when the user uses the optimal transmit power by the current resource to transmit the uplink signal, the signal can't affect the user using the resource block in downlink. The signal strength that the base station receives from the user using the current resource block is calculated secondly. Finally, according to the improved PF formula, algorithm calculates all users' priority in the current resource block, then the dispatcher selects the most appropriate user from all the users.The downlink resource allocation process of the above algorithm is prior to the uplink resource allocation process, that may cause the downlink flow and uplink flow are very unequal, so that it may be not suitable for video calls and other services. Aiming at this problem, this paper designs a full duplex resource allocation algorithm for LTE-A system based on unified priority. This algorithm calculates the uplink and downlink average rate for each user, and calculates the PF value of the uplink and the PF value of the downlink, then unifies priority ranking. Finally, according to the priority order of the users' business, dispatcher selects resource block for each user's business avoiding the interference of the previous user's business.When the two algorithms designed in this paper are applied to the CCFD community, the spectrum utilization and throughput will be improved. In the following algorithm, downlink resource allocation is have higher priority than uplink resource allocation paying more attention to the throughput of the system; The latter algorithm allocates all the resource block by the priority, Compared to the former, the latter may loss part of throughput, but the uplink traffic and the downlink traffic has very good fairness. The two algorithms designed by the paper all have low complexity that are suitable for practical application.