Performance Analysis of Cellular System Enhanced with Two-Hop Fixed Relay Nodes

Digital relaying is a promising technique to improve the signal quality in the future wireless network. A scheme of two-hop cellular network with fixed relay nodes (FRN) is investigated in this paper. Based on this scheme, signal to interference ratio (SIR) received by base station (BS) and FRN are analyzed. Theoretical analysis and simulation results show that the SIR and system spectral efficiency can be improved significantly when FRNs are employed in cellular system. We also show that the antenna height of FRN and the cell radius of BS and that of FRN influence SIR received by BS and FRN and the system spectral efficiency greatly. The proper antenna height of FRN and cell radius of BS and that of FRN are also given in this paper. Finally, the problems with current frequency planning are discussed.