Designing a uniform filter bank using multirate concept
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This presentation was created as a part of our Digital SIgnal Processing II course. The presentation is about designing a uniform filter bank using multirate concept. The presentation contains the main algorithm and subsequent MATLAB plots for for creating a uniform filter bank from a single filter prototype using multirate signal processing technique
Designing a uniform filter bank using multirate concept
- 1. Submitted by Md. Redwan Islam(1006066) Md. Rayhan Khan (1006067) Nurani saoda (1006176) Rakib Hasan (1006180) Umme Fatema (1006194) Farhan Shams (0806152)
- 2. Digital Filter Bank A digital Filter Bank is a set of digital bandpass filters either a common input or summed output. The figure shows an M-band analysis filter bank with Hk(z) as the analysis filter and Hk(z) decomposes the input signal into M-subband signals. Figure 01: Digital Filter Bank Analysis filter bank Synthesis filter bank
- 3. Uniform Filter Bank The uniform filter bank is composed of M filters which are uniformly shifted versions of the basic prototype filter. According to the definetion a uniform filter bank, Hk(ejw) = Ho(ej(w-2k/M)) ; 0 k (M-1) Where Ho(ejw) is the basic prototype filter. Figure 02: Unifomly Shifted Filter Bank
- 4. Uniform Filter Bank using Multirate Concept Polyphase Implementation of Uniform Filter Bank M-band polyphase decomposition of Hk(z), Figure 03: Polyphase implementation of a uniform DFT analysis filter bank
- 5. For k= 0,1,2. M-1, Figure 04: Uniform DFT analysis filter bank
- 6. Outputs of frequency response of some of the filters of M band Analysis Filter Bank with M=20
- 12. FFT of an input comprising of sinusoids with different magnitudes
- 20. Few major applications of uniform digital filter bank are: Digital Audio Systems Sub-band Coding of Speech and Image Signals Analog Voice Privacy Systems
- 21. The prototype filter was chosen to be FIR filter for the ease of calculation and polyphase decomposition. Commutation operation was implemented by reshaping the prototype impulse response which also formed the banks. All the outputs, e.g. magnitude response of the impulse response of the filters, magnitude response of the input and output of each bank and reconstruction observed in frequency domain, since, only frequency domain gives the perfect visualization of the signal.