An input-constrained channel is defined as the set S of finite sequences generated by a finite labeled directed graph which defines the channel. A construction based on a result of Adler, Goodwyn, and Weiss (1977) is presented for finite-state encoders for input-constrained channels. Let G=(V, E) denote a smallest deterministic presentation of S. For a given input-constrained channel S and for any rate p: q up to the capacity c(S) of S, the construction provides finite-state encoders of fixed-rate p: q that can be implemented in hardware with a number of gates which is at most polynomially large in |V|. When p/q>c(S), the encoders have order /spl les/12|V|, namely, they can be decoded by looking ahead at up to 12|V| symbols, thus improving slightly on the order of previously known constructions. A stronger result holds when p/q/spl les/c(S)-((log/sub 2/, e)/(2/sup P/q)) and S is of finite memory, where the encoders can. Be decoded by a sliding-block decoder with look-ahead /spl les/2|V|+1.
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机译：输入受限通道定义为由限定通道的有限标记的有向图生成的有限序列集S。提出了一种基于Adler，Goodwyn和Weiss（1977）结果的构造，用于输入受限通道的有限状态编码器。令G =（V，E）表示S的最小确定性表示形式。对于给定的输入受限信道S和任何比率p：q直至S的容量c（S），该结构提供了S的有限状态编码器固定速率p：q可以在具有多个门的硬件中实现，这些门最多在| V |中是多项式。当p / q> c（S）时，编码器的阶数为/ spl les / 12 | V |，即，可以通过向前看最多12 | V |来对它们进行解码。符号，因此略微改善了先前已知结构的顺序。当p / q / spl les / c（S）-（（log / sub 2 /，e）/（2 / sup P / q））和S为有限存储器时，编码器可以这样做。由具有前瞻/ spl les / 2 | V | +1的滑动块解码器解码。
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