By Topic

Optimal power allocation for a time-varying wireless channel under heavy-traffic approximation

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
$33 $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

3 Author(s)
Wei Wu ; Wireless Networking & Commun. Group, Univ. of Texas, Austin, TX, USA ; A. Arapostathis ; S. Shakkottai

This paper studies the problem of minimizing the queueing delay for a time-varying channel with a single queue, subject to constraints on the average and peak power. First, by separating the time-scales of the arrival process, the channel process and the queueing dynamics it derives a heavy-traffic limit for the queue length in the form of a reflected diffusion process. Given a monotone function of the queue-length process that serves as a penalty, and constraints on the average and peak available power, it shows that the optimal power allocation policy is a channel-state based threshold policy. For each channel state j there corresponds a threshold value of the queue length, and it is optimal to transmit at peak power if the queue length exceeds this threshold, and not transmit otherwise. Numerical results compare the optimal policy for the original Markovian dynamics to the threshold policy which is optimal for the heavy-traffic approximation, to conclude that that latter performs very well even outside the heavy-traffic operating regime.

Published in:

IEEE Transactions on Automatic Control  (Volume:51 ,  Issue: 4 )