Outage Analysis of Multi-Antenna DF Relay Systems with Finite Feedbacks over Nakagami-m Fading Channels

Some recent studies have focused on the performance of multi-antenna relay systems assuming that perfect channel state information at the transmitter(CSIT) or no CSIT of relay-destination link are available. However, there is still a lack of research on the performance of fixed relay networks with finite feedbacks. In this paper, we present the closed-form expression of outage probability for decode-and-forward (DF) multi-antenna relay networks with finite feedbacks over Nakagami-m fading channels, where relay retransmits decoded signal with transmit antenna selection or limited feedback beamforming. The moment generation function (MGF) of the combined signal-to-noise-ratio (SNR) at the destination is obtained, then the outage probabilities are derived by using numerical inversion of Laplace transform. Simulations are given to verify the correctness of the theoretical analysis.