By Topic

Real-number convolutional codes for speech-like quasi-stationary sources (Corresp.)

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)

A quasi-stationary source is one which is stationary over short periods, but changes occasionally to a new mode of stationarity; a typical example is the speech source. Convolutional codes are designed for the speech source for use with search algorithms such as the Viterbi, stack, and M -algorithms; the design is first by heuristic means and then by an empirical optimization. These codes have the same generating structure as the usual binary convolutional codes, but employ ordinary arithmetic. It is found by experiment that, at rate 2 bits/sample (which allows telephone quality speech), such codes need not have constraint length longer than five or six, which implies a generating circuit of about 1000 states. Encoding noise becomes white and uncorrelated with simple code searching; this shows that a short fixed code can successfully decorrelate waveforms from different source modes.

Published in:

Information Theory, IEEE Transactions on  (Volume:23 ,  Issue: 6 )