We characterize the orthogonal frames and orthogonal multiwavelet frames inL2Rdwith matrix dilations of the form(Df)(x)=detAf(Ax), whereAis an arbitrary expandingd×dmatrix with integer coefficients. Firstly, through two arbitrarily multiwavelet frames, we give a simple construction of a pair of orthogonal multiwavelet frames. Then, by using the unitary extension principle, we present an algorithm for the construction of arbitrarily many orthogonal multiwavelet tight frames. Finally, we give a

more »

... neral construction algorithm for orthogonal multiwavelet tight frames from a scaling function.