协议学习:lfsr
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| 协议学习:lfsr [2026/10/13 22:10] – 外部编辑 127.0.0.1 | 协议学习:lfsr [2026/10/15 21:29] (当前版本) – 外部编辑 127.0.0.1 | ||
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| ## - 多项式表 | ## - 多项式表 | ||
| - | 对于一个n nn位的LFSR,可用的抽头至少有n nn个(第0个抽头是必须的,不算数) | + | 对于一个n nn位的LFSR,可用的抽头至少有n nn个(第0个抽头是必须的,不算数)\ |
| - | 虽然一个n nn位的LFSR可以有很多种不同的抽头配置,但不是所有抽头都能使其达到最长输出序列。下表给出一些能够使LFSR达到最长反馈的抽头配置 | + | 虽然一个n nn位的LFSR可以有很多种不同的抽头配置,但不是所有抽头都能使其达到最长输出序列。下表给出一些能够使LFSR达到最长反馈的抽头配置\ |
| - | ^ LFSR位数 | + | |
| - | ^ 2 | + | | LFSR位数 |
| - | ^ 3 | + | | --- | --- | --- | --- | --- | --- | |
| - | ^ 4 | + | | 2 | 3 | 2,1 | 17 | 131,071 | 17, 14 | |
| - | ^ 5 | + | | 3 | 7 | 3, 2 | 18 | 262,143 | 18, 11 | |
| - | ^ 6 | + | | 4 | 15 | 4, 3 | 19 | 524, 287 | 19, 6, 2, 1, | |
| - | ^ 7 | + | | 5 | 31 | 5, 3 | 20 | 1,048,575 | 20, 17 | |
| - | ^ 8 | + | | 6 | 63 | 6, 5 | 21 | 2,097,151 | 21, 19 | |
| - | ^ 9 | + | | 7 | 127 | 7, 6 | 22 | 4,194,303 | 22, 21 | |
| - | ^ 10 | 1,023 | 10, 7 ^ 25 | 33, | + | | 8 | 255 | 8, 6, 5, 4, | 23 | 8,388,607 | 23, 18 | |
| - | ^ 11 | 2,047 | 11, 9 ^ 26 | 67, | + | | 9 | 511 | 9, 5 | 24 | 16,777,215 | 24, 23, 22, 17, | |
| - | ^ 12 | 4,095 | 12, 6, 4, 1, | + | | 10 | 1,023 | 10, 7 | 25 | 33,554,431 | 25, 22 | |
| - | ^ 13 | 8,191 | 13, 4, 3, 1, | + | | 11 | 2,047 | 11, 9 | 26 | 67,108,963 | 26, 6, 2, 1, | |
| - | ^ 14 | 16, | + | | 12 | 4,095 | 12, 6, 4, 1, | 27 | 134,217,727 | 27, 5, 2, 1, | |
| - | ^ 15 | 32, | + | | 13 | 8,191 | 13, 4, 3, 1, | 28 | 268,435,455 | 28, 25 | |
| - | ^ 16 | 65, | + | | 14 | 16,383 | 14, 5, 3, 1, | 29 | 536,870,911 | 29, 27 | |
| - | ^ 32 | 4, | + | | 15 | 32,767 | 15, 14 | 30 | 1, |
| + | | 16 | 65,535 | 16, 15, 13, 4, | 31 | 2, | ||
| + | | 32 | 4, | ||
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