CONSTRUCTIVE SYNTHESIS METHOD OF SEQUENCES OF LENGTH N = 20 WITH OPTIMAL WALSH-HADAMARD SPECTRUM

Abstract

The paper is devoted to the actual problem of synthesis of sequences of length N = 20, having a minimum value of the PAPR (Peak-to-Average Power Ratio) of Walsh-Hadamard spectrum, which can be used as C-codes in CDMA technology. We considered all three nonequivalent structures of Hadamard matrices of order N = 20, it was found that the form of the Hadamard matrix does not affect the cardinality of the set of sequences with the minimum value of the PAPR of Walsh-Hadamard spectrum. We investigated the properties of the discovered class of sequences on the basis of which we designed a constructive method for synthesis of the complete class of sequences with the minimum PAPR of Walsh-Hadamard spectrum. The synthesized sequences can be recommended for use as C-codes in practical CDMA systems, using Walsh functions as orthogonal transform, and also as a material for further theoretical studies aimed at constructing C-codes of greater length.