Impact of CSI on the Performance of Multi-Hop Wireless Relay Networks

The error performance, in terms of Bit Error Rate (BER), of multi-stage (multi-hop) Wireless Relay Networks (WRNs) with distributed STBC at the relay stages is presented. One relay stage is defined by a set of relays located at the same distance from the source node where the distance is measured by the number of hops. We develop the multi-stage WRN model for Amplify-and-Forward (AF) and Decode-and-Forward (DF) procedures at the relaying nodes. The system´s performance with imperfect Channel State Information (iCSI) at the receivers is also examined. Simulation results show that the tolerated error on the channel estimation increases when iCSI occurs at the channels between nodes that are far from the source node rather than close to it. This result gives good guidelines about the design of CSI knowledge at the receivers in such a way to reduce delay time and increase data rate.