Linear timeinvariant systems [7l are abbreviated as LTI and linear periodically time-varying systems as LPW. A p x r matrix A is said to be unitary (orthogonal if it i s real) if AtA = c/~, c # 0. Note that A is not restricted to be square.
Linear timeinvariantsystems [7l are abbreviated as LTI and linearperiodically time-varying systems as LPW. A p x r matrixA is said to be unitary (orthogonal if it i s real) if AtA = c/~,c # 0. Note that A is not restricted to be square.