Browse Prior Art Database

Variable Rate Decimator

IP.com Disclosure Number: IPCOM000040684D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02

Publishing Venue

IBM

Related People

Authors:
Johns, C Pearce, HB West, LP [+details]

Abstract

A method is described to provide an efficient means of data clock recovery and decimation without inducing unnecessary noise. The function of the decimator is to decrease the sample rate of a given data stream. In the demodulation process, the received signal is sampled at a rate which satisfies the nyquist sampling theory. Once the information is frequency translated from the carrier frequency band to the base band, decimation may be used. For switched telephone networks, the signal is often sampled at 9600 Hz. Many modulation techniques use a baseband bandwidth of less than 600 Hz. Sampling theory says that this baseband signal may be sampled at 1200 Hz and no information will be lost. With the advent of adaptive equalization, decimation has become an important component of the demodulation process.