An efficient type-II hybrid-ARQ protocol using punctured R-S codes for wireless ATM networks

A type-II hybrid-ARQ protocol, based on punctured Reed-Solomon (R-S) codes for the W-LLC layer of a W-ATM system, is presented. In this protocol a shortened (n,k) R-S code is decomposed into a pair of (n/2, k) punctured R-S codes which are used to protect transmissions. R-S codes are the most commonly used maximum distance separable (MDS) codes and the proposed protocol makes use of the properties of the MDS codes. The objective of the protocol is to use a low number of retransmissions in order to guarantee minimum delay, while keeping maximum throughput and low cell error rate (CER). The performance of the proposed protocol in a realistic indoor environment, taking into consideration the QoS requirements for real time applications is analysed. The analysis was carried out for a multicarrier modulation scheme (OFDM) with QPSK modulation on each carrier. The hidden Markov model (HMM) is used for modelling the physical layer of the system.