Throughput maximization by adaptive switching with modulation coding scheme and frequency symbol spreading

Abstract

This paper proposes a novel adaptive control method that maximizes throughput by optimally switching adaptive modulation and coding (AMC) and frequency symbol spreading (FSS). AMC has been extensively studied and is widely adopted as a method for optimizing throughput in fluctuating channels caused by shadowing, multipath fading and mobility. By applying AMC, communication performance can be effectively improved for varying channels. Forward error correction (FEC) is also used as communication quality improvement method. FEC is effective to improve throughput performance especially in a low SNR region. However, it has sacrificed the maximum throughput in the case of the good channel situation. FSS has been proposed as a method for suppressing the influence of frequency selective fading without degrading the maximum throughput by dispersing subcarrier symbol to all frequency components. FSS can obtain large frequency diversity gain by its diffusibility. From the simulation results, we confirm the effectiveness of the proposed method from the viewpoint of maximizing throughput.