In this paper, a new generation and a new information construction method for a modulated orthogonal sequence are suggested: the new generation method requires only integer sums and modular techniques. The autocorrelation and cross-correlation characteristics of the sequence are investigated via a new procedure. A modified sequence also having orthogonality and satisfying the mathematical lower bound of the cross-correlation is proposed, and the symbol error probability of the proposed sequence is investigated. (C) 2000 Elsevier Science B.V. All rights reserved.