Even-Length Real-Valued Cyclically Orthogonal Pseudonoise Sequences with Small Absolute Value.

This paper discusses the even-length real-valued cyclically orthogonal pseudonoise (PN) sequences with small absolute values as the PN sequence for spread spectrum communication. First, the sequence of maximum absolute value 2 with cubic or inverse phase parameters is considered. By replacing the sequence variable by the power of the primitive root and by regarding the power as the sequence variable, an orthogonal PN sequence is obtained. There exists the same number of such sequences as the number of primitive roots, and the crosscorrelation function is relatively small if the period is large. By convolving a sequence with itself, a set of sequences is obtained which has relatively small absolute value of the sequence and relatively small absolute value of cross correlation. It is proposed also to convolve a sequence with other sets of sequences. The sequence considered in this paper is suited to the digital correlation processing using the fast-Fourier transform when the period is 4, 16, 256, 65,536, ... . [ABSTRACT FROM AUTHOR]