HARQ Buffer Management: An Information-Theoretic View

Document Type

Article

Publication Date

11-1-2015

Abstract

A key practical constraint on the design of hybrid automatic repeat request (HARQ) schemes is the size of the on-chip buffer that is available at the receiver to store previously received packets. In fact, in modern wireless standards such as LTE and LTE-A, the HARQ buffer size is one of the main drivers of the modem area and power consumption. This has recently highlighted the importance of HARQ buffer management, that is, of the use of buffer-aware transmission schemes and of advanced compression policies for the storage of received data. This work investigates HARQ buffer management by leveraging information-theoretic achievability arguments based on random coding. Specifically, standard HARQ schemes, namely Type-I, Chase Combining, and Incremental Redundancy, are first studied under the assumption of a finite-capacity HARQ buffer by considering both coded modulation, via Gaussian signaling, and Bit Interleaved Coded Modulation (BICM). The analysis sheds light on the impact of different compression strategies, namely the conventional compression log-likelihood ratios and the direct digitization of baseband signals, on the throughput. The optimization of coding blocklength is also investigated, highlighting the benefits of HARQ buffer-aware transmission scheme.

Identifier

84959494642 (Scopus)

Publication Title

IEEE Transactions on Communications

External Full Text Location

https://doi.org/10.1109/TCOMM.2015.2472015

ISSN

00906778

First Page

4539

Last Page

4550

Issue

11

Volume

63

Grant

648382

Fund Ref

European Research Council

This document is currently not available here.

Share

COinS