Performance Analysis of Hybrid ARO Buffer Management

In handset modem design, HARQ buffer management techniques to significantly reduce the chip area are critical considerations for LTE-Advanced and prospective 5G technologies. In this paper, we first analyze the relationship between the mutual information of received packets and the soft combining of HARQ retransmissions, and then we propose a novel HARQ buffer management to improve the probability of successful decoding under a reduced HARQ buffer size. Compared to a full-capacity HARQ buffer, it is shown that comparable performance can be achieved by using error distributions of unsuccessful decoded blocks and early combining techniques. The results show a 50% reduction in the HARQ buffer size with a negligible degradation in the decoding performance and throughput at the target block error rate.