Implementation consideration of code division multiple access sequences

The linear span of a sequence is defined as the minimum number of stages of a linear feedback shift register required to generate the given sequence. Thus, the linear span is a measure of the complexity of the sequence structure. A large complexity or linear span is desired for security of the sequence. The binary No sequence requires nonlinear connections in addition to the linear feedback shift registers. Thus, No sequences have a large complexity and are suited for high security systems. The implementation of Gold, Kasami, and No sequences which are directly applicable for CDMA are presented and compared for complexity. An alternative to the nonlinear connection of the linear feedback shift register for the No sequences is also presented. This alternative is obtained as a direct linear feedback shift register of length equal to the linear span of the No sequence set