Forward-link Interference in CDMA-Based Cellular Networks

In this paper we have studied the in-band interference power caused by macro-cell base stations of a CDMA based cellular network. The impact of macro-cell load, location of the target receiver, service data rate of macro-cell users, and the number of sectors, on the average and standard deviation of the received interference power at a target receiver that works in the same frequency band of macro-cell base stations, is investigated. It is shown that the standard deviation of interference has a direct relation to the number of sectors as well as the data rate of service and an inverse relation to the distance of target receiver from base station. These results are then used to address a practically interesting issue, which is the utilisation of additional micro-cells working in the same band that existing macro-cells work. The achievable throughput at such micro-cells is calculated and backed by simulation. The results show that even in locations close to the macro-cell base station, in which the average interference is high, there is a possibility to sent data from micro-cell base station to users in the same frequency band.