RELATION BETWEEN RLS AND ARMA LATTICE FILTER REALIZATION-ALGORITHM AND ITS APPLICATION

In this paper, the relationship between the recursive least square (RL S) method with a U-D decomposition algorithm and ARMA lattice filter r ealization algorithm is presented. Both the RLS method and the lattice filter realization algorithm are used for the same applications, such as model identification, etc, therefore, it is expected that the latt ice filter algorithm is in some ways related to the RLS. Though some o f the proposed lattice filter algorithms have been derived by the RLS method, they do not express the relationship between RLS and ARMA latt ice filter realization algorithm. In order to describe the relation cl early, a new structure of ARMA lattice fitter is proposed. Further, ba sed on the relationship, a method of model identification with frequen cy weighting (MIFW), which is different from a previous method, is der ived. The new MIFW method modifies the lattice parameters which are ac quired without a frequency weighting and obtain the parameters of an A RMA model, which is identified with frequency weighting. The proposed MIFW method has the following restrictions: (1) The used frequency wei ghting is FIR filter with a low order. (2) By using the parameters of the ARMA lattice filter with ARMA (N,M) order and the frequency weight ing with L order, the new ARMA parameter with the frequency weighting is with ARMA(N-L,M-L) order. By using the proposed MIFW method, the AR MA parameters estimated with the frequency weighting can be obtained w ithout starting the computation again.