631 research outputs found

    The Reed-Solomon encoders: Conventional versus Berlekamp's architecture

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    Concatenated coding was adopted for interplanetary space missions. Concatenated coding was employed with a convolutional inner code and a Reed-Solomon (RS) outer code for spacecraft telemetry. Conventional RS encoders are compared with those that incorporate two architectural features which approximately halve the number of multiplications of a set of fixed arguments by any RS codeword symbol. The fixed arguments and the RS symbols are taken from a nonbinary finite field. Each set of multiplications is bit-serially performed and completed during one (bit-serial) symbol shift. All firmware employed by conventional RS encoders is eliminated

    A VLSI single chip (255,223) Reed-Solomon encoder with interleaver

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    A single-chip implementation of a Reed-Solomon encoder with interleaving capability is described. The code used was adapted by the CCSDS (Consulative Committee on Space Data Systems). It forms the outer code of the NASA standard concatenated coding system which includes a convolutional inner code of rate 1/2 and constraint length 7. The architecture, leading to this single VLSI chip design, makes use of a bit-serial finite field multiplication algorithm due to E.R. Berlekamp

    Recent advances in coding theory for near error-free communications

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    Channel and source coding theories are discussed. The following subject areas are covered: large constraint length convolutional codes (the Galileo code); decoder design (the big Viterbi decoder); Voyager's and Galileo's data compression scheme; current research in data compression for images; neural networks for soft decoding; neural networks for source decoding; finite-state codes; and fractals for data compression

    Architecture for VLSI design of Reed-Solomon encoders

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    The logic structure of a universal VLSI chip called the symbol-slice Reed-Solomon (RS) encoder chip is discussed. An RS encoder can be constructed by cascading and properly interconnecting a group of such VLSI chips. As a design example, it is shown that a (255,223) RD encoder requiring around 40 discrete CMOS ICs may be replaced by an RS encoder consisting of four identical interconnected VLSI RS encoder chips. Besides the size advantage, the VLSI RS encoder also has the potential advantages of requiring less power and having a higher reliability

    Coding for reliable satellite communications

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    Several error control coding techniques for reliable satellite communications were investigated to find algorithms for fast decoding of Reed-Solomon codes in terms of dual basis. The decoding of the (255,223) Reed-Solomon code, which is used as the outer code in the concatenated TDRSS decoder, was of particular concern

    The VLSI design of a single chip Reed-Solomon encoder

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    A design for a single chip implementation of a Reed-Solomon encoder is presented. The architecture that leads to this single VLSI chip design makes use of a bit serial finite field multiplication algorithm

    VLSI single-chip (255,223) Reed-Solomon encoder with interleaver

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    The invention relates to a concatenated Reed-Solomon/convolutional encoding system consisting of a Reed-Solomon outer code and a convolutional inner code for downlink telemetry in space missions, and more particularly to a Reed-Solomon encoder with programmable interleaving of the information symbols and code correction symbols to combat error bursts in the Viterbi decoder

    Coding for reliable satellite communications

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    This research project was set up to study various kinds of coding techniques for error control in satellite and space communications for NASA Goddard Space Flight Center. During the project period, researchers investigated the following areas: (1) decoding of Reed-Solomon codes in terms of dual basis; (2) concatenated and cascaded error control coding schemes for satellite and space communications; (3) use of hybrid coding schemes (error correction and detection incorporated with retransmission) to improve system reliability and throughput in satellite communications; (4) good codes for simultaneous error correction and error detection, and (5) error control techniques for ring and star networks
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