- Research Article
- Open Access
Cooperative Communications over Flat Fading Channels with Carrier Offsets: A Double-Differential Modulation Approach
© Manav R. Bhatnagar et al. 2008
Received: 27 October 2007
Accepted: 1 April 2008
Published: 9 April 2008
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.
To access the full article, please see PDF.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.