Downlink scheduling in fractional frequency reuse (FFR) systems

摘要

An apparatus and method are disclosed for determining the optimal bandwidth fractions for all the users in each frequency band in a wireless communication system to maximize the net sum of user utilities. User utilities are functions of average rates of users, where different averaging rules can be used for different users. The standard approach of computing an optimal scheduler strategy involves the solution of a convex optimization problem that has a complexity on the order of O(N3) for N flows. This approach is not feasible for online implementation having a large number of flows. The method of the present work employs an efficient computational algorithm that obtains the optimal bandwidth fractions in O(N) time. This feature makes the method suitable for implementation in wideband cellular systems like LTE (Long Term Evolution) and UMB (Ultra Mobile Broadband).