Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 5:00 PM ET (12:00 - 21:00 UTC). We apologize for the inconvenience.
By Topic

Differential Encoding by a Look-Up Table for Quadrature-Amplitude Modulation

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

1 Author(s)
Ruey-Yi Wei ; Dept. of Commun. Eng., Nat. Central Univ., Jhongli, Taiwan

In this paper, we propose a novel differential encoder for QAM (quadrature-amplitude modulation), by a look-up table instead of a rule. Using a table for differential encoding has the advantages of both low complexity and good error performance. We propose algorithms to construct the table for maximizing the minimum noncoherent distance and minimizing the number of different data bits between two codewords with small noncoherent distance. For 16QAM and 32QAM, we show that the differential encoders obtained by the proposed algorithms are optimal in terms of minimum noncoherent distance. Differential detectors for QAM, including a reduced-complexity two-symbol detector and multiple-symbol detectors, are proposed as well. Simulation results of 16QAM show that the proposed differential encoder provides significant gain over existent differential encoders as expected by distance analysis, and the proposed low-complexity multiple-symbol differential detector can further improve the error performance.

Published in:

Communications, IEEE Transactions on  (Volume:59 ,  Issue: 1 )