Linear precoding techniques for DF based relay networks

Abstract

We consider linear precoding matrix design problem for decode-and-forward (DF) based multiple-input multiple-output(MIMO) relay systems where include direct link from source to destination and multiuser cellular relay systems where the available information at the base station and the relay is asymmetric. For both cases, linear precoding matrices are designed by allocating power and adjusting direction based on proper amount of channel state information (CSI). Consequently, the proposed schemes outperform the conventional relaying schemes in all SNR regime. Furthermore, numerical results show that the proposed scheme approaches an ideal scheme in terms of capacity using dirty paper coding (DPC) in the information asymmetric configuration. An mathematical framework for the analysis of the proposed technique is also presented.