PG-LDPCC Codes in Turbo Equalizer Systems: Trade-Off between Design Parameters of the Protograph and the Permutation Size

Turbo equalization is a technique to enable wireless transmissions by means of an iterative exchange of information between several components at the receiver incorporating a soft equalizer. The performance achievable can be improved by adjusting the components related to one another. The focus of this paper lies on the study of the possible adjustments to terminated protograph-based Low- Density Parity Check convolutional codes. Some of the parameters (syndrome former memory ms, termination length L) are related to the underlying terminated convolutional protograph, while others (like permutation size P) come into play during the actual code construction process. Compared to our previous work where the design parameter of the protograph is the only focus of the study, this work will also focus on the final constructed codes and their performance. In order to evaluate the code´s performance, the length of the code is an important property. Along with the permutation size P and the protograph parameters (ms, L), it is possible to make a fair comparison between the codes and to decide in favor of the code used to achieve the desired requirements of code length, performance, and code rate.