Weight complexity analysis of binary sequence with period 2~p q

Weight complexity is an important index to measure the stability of linear complexity. Weight complexity W C 1 (S ∞) and the lower bound of the binary sequence with period  2 p q  are given in this paper, where q is a prime number. It is shown that many sequences with period  2 p q  are non stable, and only one symbol substitution will cause  2 p q  change of linear complexity. The result is an extention on weight complexity of a sequence with period 2 n.