By Topic

Performance of OFDM with M-QAM modulation and optimal loading over Rayleigh fading channels

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)
Digham, F.F. ; Minnesota Univ., Minneapolis, MN, USA ; Hasna, M.O.

We present optimum bit and power loading algorithms for orthogonal frequency division multiplexing (OFDM) systems using an M-ary quadrature amplitude modulation (M-QAM) scheme. Several scenarios for the amount of channel state information (CSI) available at the transmitter are investigated. These include statistical, quasi-statistical, and instantaneous CSI. The optimality criterion used is minimizing the average/instantaneous total bit error rate while fulfilling total power budget and spectral efficiency constraints. Numerical examples show that optimizing the allocation of bits/power greatly enhances the system performance in the instantaneous CSI mode while not much gain is expected in either statistical or quasi-statistical modes. They also show that the system performance is more sensitive to bit allocation than to power allocation. Furthermore, it is shown that the quasi-statistical-CSI based loading yields the best performance given the complexity/performance tradeoff.

Published in:

Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th  (Volume:1 )

Date of Conference:

26-29 Sept. 2004