This paper deals with the problem of constructing multidimensional biorthog
onal periodic multiwavelets from a given pair of biorthogonal periodic mult
iresolutions. Biorthogonal polyphase splines are introduced to reduce the p
roblem to a matrix extension problem, and an algorithm for solving the matr
ix extension problem is derived. Sufficient conditions for collections of p
eriodic multiwavelets to form a pair of biorthogonal Riesz bases of the ent
ire function space are also obtained.