An adaptive error control system using hybrid ARQ schemes

A simple and efficient system utilizing the class of Hamming codes in a cascaded manner is proposed to provide high throughput over a wide range of channel bit error probability. Comparisons with other adaptive schemes indicate that the proposed system is superior from the point of view of throughput, while still providing the same order of reliability as an ARQ (automatic repeat request) system. The main feature of this system is that the receiver uses the same decoder for decoding the received information after each transmission while the error-correcting capability of the code increases. As a result, the system is kept to the minimum complexity and the system performance is improve

An adaptive error control system using hybrid ARQ schemes

A simple and efficient system utilizing the class of Hamming codes in a cascaded manner is proposed to provide high throughput over a wide range of channel bit error probability. Comparisons with other adaptive schemes indicate that the proposed system is superior from the point of view of throughput, while still providing the same order of reliability as an ARQ (automatic repeat request) system. The main feature of this system is that the receiver uses the same decoder for decoding the received information after each transmission while the error-correcting capability of the code increases. As a result, the system is kept to the minimum complexity and the system performance is improve

Turbo Codes Construction for Robust Hybrid Multitransmission Schemes

In certain applications the user has to cope with some random packet erasures due, e.g., to deep fading conditions on wireless links, or to congestion on wired networks. In other applications, the user has to cope with a pure wireless link, in which all packets are available to him, even if seriously corrupted. The ARQ/FEC schemes already studied and presented in the literature are well optimized only for one of these two applications. In a previous work, the authors aimed at bridging this gap, giving a design method for obtaining hybrid ARQ schemes that perform well in both conditions, i.e., at the presence of packet erasures and packet fading. This scheme uses a channel coding system based on partially-systematic periodically punctured turbo codes. Since the computation of the transfer function and, consequently, the union bound on the Bit or Frame Error Rate of a partiallysystematic punctured turbo code becomes highly intensive as the interleaver size and the puncturing period increase, in this work a simplified and more efficient method to calculate the most significant terms of the average distance spectrum of the turbo encoder is proposed and validated