equivalence of a special subspace method and the initial estimate proposed by Hannan and Rissanen. Finally, a simulation study comparing two subspace methods and the maximum- likelihood method is performed.
The paper consists of three parts. In part one we give a consistency proof for subspace methods, in part two we show the asymptotic equivalence of a special subspace method and the initial estimate proposed by Hannan and Rissanen. In part three a simulation study comparing two subspace methods and the maximum likelihood method is performed.