Search and Modification of Code Sequences Based on Circulant Quasi-orthogonal Matrices

In order to improve noise-immune encoding in telecommunication channels and recognition of a useful signal in significant interference conditions, there is a need for new, advanced coding sequences. This paper is devoted to the problems of searching and examining new error-correcting codes constructed on the basis of circulant quasi-orthogonal matrices and used for phase modulation of signals in the radio channel. The paper presents requirements for well-known coding sequences for lengths greater than 13 bits. The estimates of characteristics of the new coding sequences allow us to compare them with other well-known coding sequences that are widely used in practice. The advantages of the codes, obtained in this work, are discussed in the aspects of improving the correlation characteristics, their detection, and noise immunity in the radio channels of contemporary systems.