A method for initializing free parameters in lattice structure of linear phase perfect reconstruction filter bank

•We systematically study the initialization of the free parameters in a higher-order LPPRFB by those in a lower-order one.•The lower order in the proposed method is not limited to be zero.•The lower-order filter bank is not restricted to be WHT or DCT filer bank.•The difference between the higher order and the lower order can be any integer allowed by an LPPRFB system.•The filter banks yielded by our method show comparable or even better performance compared with published LPPRFBs.

Since the optimization of the free parameters in the lattice structure of linear phase perfect reconstruction filter bank (LPPRFB) is commonly highly nonlinear, the initialization of the free parameters is important before starting the optimization. We systematically study the initialization of the free parameters, following the way that initializes the free parameters in a higher-order LPPRFB by those in a lower-order one. The proposed method is carried out in two steps: formulating the relation between the higher-order and the lower-order LPPRFBs in terms of polyphase matrices, and then implementing the initialization based on the relation. Design examples show that, compared with published LPPRFBs, the filter banks yielded by our method show comparable or even better performance.