Skip to main content

Patent Review on Multi-rate Digital filter for audio sample-rate conversion

Patent name: Multi-rate Digital filter for audio sample-rate conversion
US Patent No: 6,487,573 B1

This patent emphasises on method for providing sample rate conversion filter on an input stream of sampled data provided at a first rate, to produce an output stream of data at a second rate different from the first rate. The input stream of sampled data is operated on with a first low order interpolation  filter routine to produce first intermediate data
 The stream of intermediate data is operated on routine, having a substantially small number of operations to calculate the to produce a second stream of intermediate data. The Second Stream of intermediate data is Operated on  routine to produce the output stream of data.

Comments

  1. UnknownMay 1, 2017 at 9:34 PM

    Low Pass Filters are used in most of the equalizers as well for the same purpose.

    ReplyDelete

Post a Comment

Popular posts from this blog

FIR FILTER DESIGN USING WINDOWING METHOD

The aim was Linear Phase FIR Filter design using window function. In this experiment we designed a digital filter using windowing technique and studied the spectrum of the filter. The input specifications were given as For LPF / HPF filter Design : (1) Pass band Attenuation (Ap) (2) Stop band Attenuation (As ) (3) Pass band Frequency (Fp) in Hz (4) Stop band Frequency (Fs) in Hz (5) Sampling Frequency in Hz  For BPF / BSF filter Design : (1) Pass band Attenuation (Ap) (2) Stop band Attenuation (As ) (3) Pass band Frequency (Fp1, Fp2) in Hz (4) Stop band Frequency (Fs) in Hz (5) Sampling Frequency in Hz    F or the phase spectrum we concluded that it is linear for FIR filter. Also the observed values of As and Ap are close to the input values
3 comments
Read more

OVERLAP ADD METHOD/OVERLAP SAVE METHOD

The aim   of this experiment was to perform filtering of Long Data Sequence using Overlap Add Method and Overlap Save Method. We implemented the filtering of Long Input Sequence using Overlap Add / Overlap Save Algorithm. The Input Specifications were given as length of long data sequence and signal values and length of impulse response M and Signal values. We concluded that Overlap Add Method(OAM) and Overlap Save Method(OSM) are efficient methods to calculate the convolution between long length signal and finite impulse signal.
2 comments
Read more

DESIGN OF BUTTERWORTH FILTER

The aim of this experiment was designing analog and digital Butterworth filter. We designed a digital filter from analog filter and studied the aliasing effect due to sampling in Impulse Invariant Method and the frequency warping effect in BLT Method. The Input Specifications were given as (1) Pass band Attenuation  (2) Stop band Attenuation  (3) Pass band Frequency (4) Stop band Frequency  (5) Sampling Frequency        We arrived at a conclusion that for both low pass and high pass filter, poles lie inside the unit circle. Hence both the filters are stable. But we also observed in the result that the values of Ap and As are not approximately same. Hence for better stability the order of the filter needs to be increased.
2 comments
Read more