Cycle structure analysis of QC-IRA-B codes based on circulant permutation matrices

Abstract

Based on analyzing the cycle structure of QC-IRA-B codes, QC-IRA-d code was presented in another paper without analysis process in detail and this kind of code is suitable for channel coding scheme of navigation data of COMPASS. This paper analyzes the cycle structure of QC-IRA-B codes based on circulant permutation matrices. The analysis of this paper shows that some special cycle structures result in lots of low-weight code words which worsen the error-correcting performance of QC-IRA-B codes. This paper also shows why QC-IRA-d codes have good error-correcting performance. © 2012 Springer-Verlag.