Coding performance of HARQ with BICM — Part II: LTE circular buffer rate matching & extension

This paper discusses the design, performance optimization and potential extensions of the LTE HARQ operations. The HARQ retransmission behavior of all 764 possible LTE code blocks is classified into 12 types based on two easily and already computed quantities in the standard. Using with the unified information-theoretical quantification of various HARQ gains discussed in the companion paper, the optimal retransmission settings for the LTE system are designed. The analytical framework is further applied to optimize potential modifications to the LTE standard for enhanced retransmission performance. Numerical results are provided to verify these optimized settings.