Optimization of Frame Length in OFDMA Systems Taking into Account the Control Signaling Cost

Dynamic OFDMA has been recognized as a promising technique for improving the performance of future wireless cellular systems. However, this potential performance improvement comes at the cost of additional signaling overhead, which can have a non-negligible effect on the system efficiency. In this paper, we propose a new method for optimizing the frame length for the downlink in OFDMA systems. The method maximizes the system efficiency by taking into account both the channel conditions and the amount of signaling overhead needed to deliver scheduling maps to the users. We formulate the frame length optimization problem mathematically. By exploiting the structure of this problem, we develop an algorithm that solves a sequence of dynamic programming problems. Simulation results reveal some insight into fundamental limitations as well as provide guidelines for the design of dynamic OFDMA systems.