2-D FILTER STABILITY-TESTS USING POLYNOMIAL ARRAY FOR F(Z1Z2) ON [Z1] = 1

A polynomial array for F(z1, z2) on (z1) = 1 is developed with a simple and systematic constructing procedure to overcome the difficulties in the implementation of algebraic methods for 2-D filter stability tests. No conjugate polynomials (or their coefficients) required in previous procedures are necessary in the proposed method. It is easy to program regardless of the orders of F(z1, z2). A simple procedure is also given for converting polynomial entries in the first column of the array from z1 domain into x1 domain, where x1 = (z1 + z1(-1)/2. Stability tests are then carried out on these real polynomials.