Skip to content


  • Research Article
  • Open Access

Cooperative Communications over Flat Fading Channels with Carrier Offsets: A Double-Differential Modulation Approach

EURASIP Journal on Advances in Signal Processing20082008:531786

  • Received: 27 October 2007
  • Accepted: 1 April 2008
  • Published:


We propose double-differential (DD) modulation for the amplify-and-forward protocol over Nakagami- fading channels with carrier offsets. We propose an emulated maximum ratio combining (EMRC) decoder, which could be used by the double-differential receiver in the absence of exact channel knowledge. Approximate bit error rate (BER) analysis is performed for the proposed double-differential modulation-based cooperative communication system. The proposed double-differential system is immune to random carrier offsets, whereas the conventional single-differential modulation-based cooperative system breaks down. In addition, the proposed scheme is able to perform better than the same rate training-based cooperative system which utilizes training data for finding estimates of carrier offsets and channel gains.


  • Error Rate
  • Information Technology
  • Training Data
  • Communication System
  • Quantum Information

Publisher note

To access the full article, please see PDF.

Authors’ Affiliations

UniK - University Graduate Center, University of Oslo, P.O. Box 70, 25 Instituttveien, 2027 Kjeller, Norway