LARGE FAMILIES OF QUATERNARY SEQUENCES WITH LOW CORRELATION

A family of quaternary (Z(4)-alphabet) sequences of length L = 2(r) - 1, size M greater than or equal to L(2) +3L+2, and maximum nontrivial correlation parameter C-max less than or equal to 2 root L + 1 + 1 is presented. The sequence family always contains the four-phase family A . When r is odd, it includes the family of binary Gold sequences. The sequence family is easily generated using two shift registers, one bin ary, the other quaternary. The distribution of correlation values is p rovided. The construction can be extended to produce a chain of sequen ce families, with each family in the chain containing the preceding fa mily. This gives. the design flexibility with respect to the number of intermittent users that can be supported, in a code-division multiple -access cellular radio system. When r is odd, the sequence families in the chain correspond to shortened Z(4)-linear versions of the Delsart e-Goethals codes.