Long-term Fading Statistics-Based Power Allocation for Fixed Decode-and-Forward Relays
Hyung Yun Kong, Vo Nguyen Quoc Bao · 2008
This paper considers 2-hop wireless cooperative communications networks with fixed decode-and-forward relays. Specifically, we first derive the closed-form BER expression for theoretically evaluating the end-to-end performance of these networks. Then, based on this expression and long-term fading statistics, we propose a power allocation method for source and relay. Such a method brings about multiple advantages in term of spectral efficiency and implementation complexity over other power allocation methods based on instantaneous fading statistics. A variety of numerical results reveal that the cooperative communications scheme with the proposed power allocation significantly outperforms that with the equal power allocation and the direct transmission scheme for any position of the relay subject to the same total transmit power constraint.