The Capacity Analysis Of The Two-hop Relay Cellular Network Based On TDD-CDMA

Multihop Cellular Networks(MCNs) is a heterogeneous network which is the combine of Cellular networks and Multihop relay networks. Cellular networks is based on a base station as the core of the cell which can provide wide area network coverage for mobile users with random distribution. Multihop relay networks depend on many wired-less devices inside the cell to relay signals through multiple hops from source to destination. MCNs were proposed to overcome inherent drawbacks in cellular networks such as congestion, dead spots and near-far effect to increased capacity. There are so many types of cellular network, the performance of Code Division Multiple Access(CDMA)is greatly influenced by interference, so we use it as our network model for research.At first,this thesis will introduce the mode of the MCN based on CDMA and deduce the formula of the up-link inter and intra interference in this mode. There are two kinds of the terminals’ transmission power---fix power and power control. under the power control mode, it deduces the average transmission power formula of the terminals. For convenience of analysis, it simplifies the MCN to two-hop relay cellular network model and proposes two kinds of time-slot scheduling algorithm—synchronization time slot scheduling and asynchronous time slot scheduling.According to the formula of interference MCN model it deduced before, the interference formula of two-hop relay cellular network based on Time Division Duplex Code Division Multiple Access(TDD-CDMA) with different time-slot scheduling has been found. According to the analysis of the interference, it gives the way to calculate the capacity of the model. At the end, this thesis will simulation analysis the capacity of two-hop relay cellular network model and verify the effect of different parameters to the capacity of the two-hop relay cellular network under different time-slot scheduling algorithm. The results show that the synchronization time slot scheduling is suit for the cell which has heavy-load in interior zone and the asynchronous time slot scheduling is suit for the cell which has heavy-load in the exterior zone.