Single parameter model for loaded multicarrier systems

Due to its excellent spectral efficiency, multicarrier modulation has been proposed for a variety of emerging wireless systems that provide broadband communications. Adaptive bit loading improves the performance of this modulation scheme by taking advantage of the frequency selective nature of the wireless channel. To design the complete broadband system, it is crucial to characterize the performance after adaptive bit loading. Simulating the full-blown loaded multicarrier modulation together with the upper layer protocols would be too time consuming, unless we have a simple equivalent model. We derive such a model and illustrate how it accurately predicts the performance of a physical layer based on loaded multicarrier modulation. In fact, we prove that its behavior corresponds to that that of a single carrier system with a log-normally fading channel tap. Besides for simulation purposes, this model is also valuable for mathematical analysis.