Binary sequences with large family size and high linear complexity for spread spectrum communication systems

Spreading sequences with low correlation, high linear complexity and large family size, in a direct-sequence spread spectrum communication system, help to minimize multiple access interference, increase security degree of system and enlarge user number, respectively. In this paper, a family of binary sequences with 5-valued low correlation, large family size and high linear complexity is presented. The proposed sequences have the same correlation distribution as the sequences in Ref. [6], and include the latter and No sequences as special cases. Although a closed-form mathematical expression regarding linear complexity of the proposed sequences can not be given, the simulation results by a computer show that the number of the proposed sequences, whose linear complexity is not less than the highest that of the sequences in Ref. [6], is quite larger than one of the sequences with the highest linear complexity in Ref. [6].