A Hybrid ARQ Using Double Binary Turbo Codes

The reliability of a data communication can be improved by using an automatic repeat request (ARQ) protocol, in which the receiver requests the retransmission of data packets when an error is detected in the received data. The hybrid ARQ (HARQ) scheme combines an ARQ and an error correction coding [1]. Turbo codes proposed by Berrou et al. in 1993 [2] show an error correction capability approaching the Shannon limit. Double binary turbo codes proposed by Berrou et al. [3] show an improved error correction capability and a fast decoding compared with binary turbo codes. The turbo coding has been successfully applied to a HARQ system thanks to its rate compatibility [4] obtained by a simple puncturing. The HARQ using turbo codes for error correction is generally called a turbo HARQ. Narayanan et al. [5] proposed a binary turbo HARQ scheme using binary turbo codes for error correction, and many research activities have been conducted on the binary turbo HARQ schemes [6]. In this letter, we propose an IR-HARQ scheme using double binary turbo codes for error correction, where the puncturing rule is designed to produce a high throughput over all Es/N0. It is shown by simulations that the proposed HARQ provides a higher throughput at all Es/N0 than the binary turbo HARQ and provides an extra coding gain over that achieved by turbo codes only.