Planning and performance evaluation of OFDM/OFDMA multi-carrier cellular systems with femto cells

Femto-cell can be considered as a home base station (BS) that can be installed to improve bandwidth availability and coverage for enabling new applications in the home. Actual 3G-based femto BSs are seen as an alternative to Wi-Fi hotspots and/or as a complementary technology. In the very near future 3G and 4G cellular networks will converge on OFDM/OFDMA wireless access interface. Thus the planning and the performance evaluation of OFDM/OFDMA cellular system including femto cells is of interest. This paper is focused on performance evaluation of OFDM-/OFDMA cellular systems in the presence of interference due to femto cells. Due to the generally scarce spectrum availability for Broadband Wireless Access systems, such as WiMAX, in the frequency band below 10 GHz, it is assumed that femto cells and cellular BSs transmit on the same band. The considered performance figure is the outage probability which is calculated as a function of the "effective exponential SINR". An effective methodology for determining the system parameter for a cellular system with femto cells is presented. Such methodology also allows the evaluation of the system capacity of an already existing cellular network when femto cells become (randomly) active in the area.