On the Joint Use of Turbo codes and Optimal Signals with Increased Symbol Rate

Abstract

In this work the joint use of turbo codes and optimal signals is considered. Due to high spectral efficiency provided by optimal signals and improved energy efficiency caused by turbo coding it is possible to get closer to the Shannon limit. The degree of approaching is defined as the minimal distance between the Shannon curve and the point which coordinates are values of spectral and energy efficiency. The results are also compared to “classic” BPSK signals. It is shown that optimal signals with turbo coding are 7.6 times closer to the Shannon limit than “classic” BPSK signals for the same data rate. Parameters of signals with better approaching to the Shannon limit are found.