  A factorization of the inverse of a Hermetian positive definite matrix based
on a diagonal by diagonal recurrence formulae permits the inversion of Toeplitz
Block Toeplitz matrices using minimized matrix-vector products, with a
complexity of ((n1)^3)((n2)^2), where n1 is the block size, and n2 is the block
matrix size. A 2D levinson algorithm is introduced that outperform Wittle,
Wiggins and Robinson Algorithm
