On the diversity order of non-orthogonal amplify-and-forward over block-fading channels

Abstract--In this paper, we deal with the performance of nonorthogonal Amplify-and-Forward protocols over block-fading channels (BFNAF), where the source retransmits the same data during cooperation in order to increase spatial diversity. Despite the additional diversity degree that is offered by the channel, channel inversion amplification schemes are not always able to increase the diversity gain of the system due to the high correlation that can result in the two simultaneous transmissions. It is proven that this diversity loss is related to a poor sourcerelay link that via the relay amplification process affects the third available diversity branch corresponding to the second source transmission. In order to resolve this problem, we integrate a fixed gain amplification factor in the BFNAF scheme which efficiently uses the additional diversity degree of the channel and recovers the diversity loss associated with channel inversion schemes. This new BFNAF scheme offers spatial diversi...

• Type: Journal
• Year: 2010
• Where: TWC
• Authors: Ioannis Krikidis, John S. Thompson, Steve McLaughlin
• Keywords: Additional Diversity Degree, Artificial Intelligence, Diversity Loss, Spatial Diversity, TWC 2010