On the design of implementation of turbo-coded Hybrid-ARQ

The problem of the efficient use of Hybrid Automatic-Repeat-reQuest (Hybrid-ARQ)in wireless communication has attracted a considerable amount of research. In thisthesis, the use and implementation of turbo codes as the Forward Error Correction(FEC) code for Hybrid-ARQ is investigated. The major accomplishments of theresearch include both the analysis and implementation of turbo Hybrid-ARQ. Thethesis begins by obtaining a tractable bound for the performance of turbo codes withM-ary Quadrature-Amplitude-Modulation (M-ary QAM). The research considers thedesign problem of turbo coded Hybrid-ARQ optimized for AWGN and fading channels.The design problem of turbo Hybrid-ARQ in wideband channels is consideredand an optimization strategy is proposed based on Orthogonal-Frequency-Division-Multiplexing (OFDM). The research also presents a novel rate scalable encoder structurethat optimal selects a disparate but optimal pair of component codes given thechannel conditions. A second part of the thesis considers the implementation of turboHybrid-ARQ in Very Large Scale Integration (VLSI ) systems. A design for a singlearchitecture for Type-I and Type-II turbo Hybrid-ARQ is suggested in addition toapproaches for improving performance of the Soft-Output-Viterbi-Algorithm(SOVA)decoder core. The research also proposes a SOVA decoder architecture that exploitsreliability information to select between the SOVA and bi-directional SOVA