A systematic technique for designing prototype filters for perfect reconstruction cosine modulated and modified DFT filter banks
نویسندگان
چکیده
Optimizing the angles for the lattice structures in the prototype filter for perfect-reconstruction cosine-modulated and modified DFT filter banks is a very difficult task because there exist several local optima. In order to get around this problem, this paper describes an efficient systematic technique for designing prototype filters in the least-mean-square sense. First, the few angles for the two-channel case are optimized using various techniques for numerous filter lengths and stop-band edge frequencies. The resulting angles are expressed as polynomials of the stop-band edge for later use. After knowing the angles for the two-channel case, corresponding filter banks having several channels can be effectively generated by gradually increasing the number of channels and by properly using the result of the previous step as a start-up solution for the present step. This approach allows us to design very fast at least good locally optimized prototype filters for banks having many channels and long channel filters.
منابع مشابه
An efficient approach for designing nearly perfect-reconstruction low-delay cosine-modulated filter banks
An efficient approach is described for optimizing the stopband response of the prototype filter for low-delay critically sampled cosine-modulated filter banks in the least-mean-square sense subject to the maximum allowable aliasing and amplitude errors. These low-delay filter banks differ from orthogonal cosine-modulated filter banks, where the filter bank delay is equal to the prototype filter...
متن کاملAn efficient approach for designing nearly perfect-reconstruction cosine-modulated and modified DFT filter banks
Efficient two-step algorithms are described for optimizing the stopband response of the prototype filter for cosine-modulated and modified DFT filter banks either in the minimax or in the least-mean-square sense subject to the maximum allowable aliasing and amplitude errors. The first step involves finding a good start-up solution using a simple technique. This solution is improved in the secon...
متن کاملDesign of multi-channel near-perfect-reconstruction transmultiplexers using cosine-modulated filter banks
The paper considers the design of nearly perfect reconstruction transmultiplexer systems based on cosine-modulated filter banks. Under the same scheme of cosine-modulation, several families of transmultiplexer systems are derived, the main difference of which is the prototype filter. We show several ways of obtaining this filter and we also propose a new technique for designing high-quality pro...
متن کامل2M-Band Interleaved DFT Modulated Filter Banks with Perfect Reconstruction
In this paper, we propose a new family of perfect reconstruction (PR) complex filter banks, named interleaved discrete Fourier transform modulated filter banks (Interleaved DFT-FBs). In the filter banks, the analysis filters are generated by interlaced exponential modulating two different analysis prototype filters, and the synthesis filters are generated by two different synthesis prototype fi...
متن کاملModulated M-Channel FIR Filter Banks Utilizing the Frequency Response Masking Approach
The frequency-response masking (FRM) approach was introduced as a means of generating narrow transition band linear-phase FIR filters with a low arithmetic complexity. This paper proposes an approach for synthesizing modulated maximally decimated FIR filter banks utilizing the FRM technique. For this purpose, a new class of FRM filters is introduced. Filters belonging to this class are used for...
متن کامل