A method to design efficient puncture-constrained interleavers for turbo codes (TCs) is introduced. Resulting TCs profit from a joint optimization of puncturing pattern and interleaver to achieve an improved error rate performance. First, the puncturing pattern is selected based on the constituent code Hamming distance spectrum and on the TC extrinsic information exchange under uniform interleaving. Then, the interleaver function is defined via a layered design process taking account of several design criteria such as minimum span, correlation girth, and puncturing constraints. We show that applying interleaving with a periodic cross connection pattern that can be assimilated to a protograph improves error-correction performance when compared to the state-of-the-art TCs. An application example is elaborated and compared with the long term evolution (LTE) standard: a significant gain in performance can be observed. An additional benefit of the proposed technique resides in the important reduction of the search space for the different interleaver parameters.

International audienceThree of the most common interleavers for Turbo Codes (TCs) are Dithered Relative Prime (DRP) interleavers, Quadratic Permutation Polynomial (QPP) interleavers and Almost Regular Permutation (ARP) interleavers. In this paper it is shown that DRP and QPP interleavers can be expressed in the ARP interleaver function form. Furthermore, QPP interleavers can be seen as a particular case of ARP interleavers, in which the values of the periodic shifts follow the quadratic term of the QPP interleaver function. Some application examples of the equivalent expressions are provided. Particularly, in the QPP interleaver case, the different instances in the Long Term Evolution (LTE) standard are considered. Obtained results are useful when investigating a suitable and general permutation model for TCs

International audienceA method to design channel interleavers based on span properties and mutual information is presented. Resulting interleavers enjoy better burst error control and can mitigate the effect of regular error patterns. An application example based on the 2nd generation Digital Video Broadcasting Terrestrial (DVB-T2) standard is elaborated. Four channel interleaving structures are generated, resulting from a joint optimization of the interleaver span properties in the time and frequency domains, while guaranteeing good interaction with the bit interleaver. Proposed solutions are compared to the standardized DVB-T2 channel interleaver in terms of performance, latency and complexity. A significant improvement can be observed in severe channel conditions, especially over time and frequency-selective channels with erasures. Moreover, the complexity and latency of the proposed channel interleavers are reduced compared to the original DVB-T2