k-错线性复杂度是衡量序列伪随机性的重要指标之一.对线性复杂度第一下降点为4的以2的方幂为周期的二元序列,本文通过分析Games-Chan算法,给出了其4-错线性复杂度的所有可能取值形式以及具有给定4-错线性复杂度的序列的计数.更进一步,给出了其4-错线性复杂度的期望.结果表明,其4-错线性复杂度的期望与线性复杂度相差不大.
The k-error linear complexity is one of the important measures for assessing the pseudorandom properties of sequences.For binary sequences with period a power of 2,of which the first decreasing point of the linear complexity is 4,the possible values of the 4-error linear complexity and the number of sequences with given 4-error linear complexity are established based on the Games-Chan algorithm.Moreover,the expected value of the 4-error linear complexity is also provided.The results show that the 4-error linear complexity is close to the linear complexity.