Perfermance Evaluation Of Frequency Planning In Cellular Architecture Based On Fixed Relay

This paper focuses on wireless cellular system based on digital fixed relay, studys the key issues in cellular relay network, and gives a thorough and comprehensive study on the designment of cellular architecture with fixed relays and frequency planning schemes.Based on cellular systems with relay, a novel cellular architecture, termed Cellular Architecture Based on Sector Relay (CASR), is proposed in this paper. In CASR, fixed relays equipped directional antenna are located at the vertex of the hexagonal cell for sectorization and shared by three adjacent cells. By this method, better services can be provided to cell-edge users, and inter-cell handover process can be more convenient.Compared with traditional cell architecture, frequency planning scheme in relay-based cell architecture is more important, because extra frequency resources are needed to allocate to relay nodes, which is not existed in traditional cell architectures. Based on CASR the paper has proposed two frequency planning schemes:FPU-1 scheme and FPU-7. Interference analysis and performance evaluation are investigated for one-hop and two-hop communication situations. The results of system-level simulations for FPU-1, FPU-7 and traditional scheme prove that the two schemes proposed in this paper, compared with traditional scheme, can effectively reduce the inter-cell interference and increase system throughput. In particular, proposed schemes can effectively improve the performance of cell edge users.In addition, based on CASR structure, this article has considered the situation that directional antennas are used by base stations, and proposed an enhanced CASR structure (ECASR). A novel frequency planning scheme based on ECASR is also proposed. The results of system-level simulations prove that the performance of the novel frequency planning scheme is better than traditional MFSR, and the SINR performance is similar to FPU-1 and FPU-7. The system throughput is higher than FPU-1 and FPU-7, for the spectrum utilization performance is enhanced.