We present an analytical framework to evaluate the system capacity of two cellular systems in an interference-limited environment: a single-user system with and without other-cell interference and a multiuser system with and without other-cell interference. In a multiuser system, we adopt the multiuser diversity scheme. We derive closed-form expressions of the system capacity for the above four cases. The analytical results agree well with simulation result. Other-cell interference with large variances increases the achievable throughput, while the averaged other-cell interference reduces the system capacity. In addition, we show that a fairness problem arising between inner cells and outer cells in the cellular network can be improved by using other-cell interference in the multiuser system. Therefore, the multiuser diversity scheme can be a good candidate for future cellular networks.