A practical method for approaching the channel capacity of constrained channels
A practical method for approaching the channel capacity of constrained channels
复制标题
一种逼近受限信道信道容量的实用方法
DOI：
10.1109/18.623139
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
Kees A. Schouhamer Immink
中科院分区：
文献类型：
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作者：
Kees A. Schouhamer Immink
提出了一种新的编码技术，该技术使用非常长的码字将用户信息转换成受约束的序列。通过颠倒差错控制码和约束码的传统层次结构，避免了由长码字的使用所导致的巨大的差错传播。新技术的例子集中在（d，k）-约束码。提出了一种有效存储的枚举编码方案，用于将用户数据转换为长dk序列，反之亦然。对于dk游程长度有限的代码，估计编码效率与编码器和解码器的复杂性之间的关系。我们表明，对于最常见的d，k值，低于0.5%的信道容量的码率可以通过使用硬件主要由ROM查找表的大小为1 kbyte。对于选定的d和k值，查找表的大小要小得多。本文最后给出了一个速率为256/466（d=2，k=15）的码的数值例子，与传统的速率为1/2（2，7）的码相比，该码的速率提高了10%。
A new coding technique is proposed that translates user information into a constrained sequence using very long codewords. Huge error propagation resulting from the use of long codewords is avoided by reversing the conventional hierarchy of the error control code and the constrained code. The new technique is exemplified by focusing on (d, k)-constrained codes. A storage-effective enumerative encoding scheme is proposed for translating user data into long dk sequences and vice versa. For dk runlength-limited codes, estimates are given of the relationship between coding efficiency versus encoder and decoder complexity. We show that for most common d, k values, a code rate of less than 0.5% below channel capacity can be obtained by using hardware mainly consisting of a ROM lookup table of size 1 kbyte. For selected values of d and k, the size of the lookup table is much smaller. The paper is concluded by an illustrative numerical example of a rate 256/466, (d=2, k=15) code, which provides a serviceable 10% increase in rate with respect to its traditional rate 1/2, (2, 7) counterpart.