Inter-System Interference Effect on WiMAX Network Performance

Systems coexistence is becoming a very challenging issue. Due to the imperfections of the RF (radio frequency) front-end filters, the out-of-band spurious emission from the transmitter is occurred, as well as the receiver selectivity inaccuracy. Those two factors cause different interference levels depending on the transmitted power, the duplex mode of the technology, and also on the distance between terminals. We present in this paper an evaluation to the interference caused by the inter-system coexistence using a mathematical model for both the out-of-band spurious emission, and the receiver selectivity. This framework is then used to estimate the inter-system interference impact on the WiMAX CPEs (customer premises equipment), and hence on the performance of a WiMAX network in terms of capacity. Monte-Carlo approach has been used to estimate the WiMAX network capacity using a simple system level simulator. Different simulation scenarios are considered, all in the DL (downlink) direction. Coexistence with other systems such as Bluetooth is perceived to impact the WiMAX network. The users' applications have also revealed their impact on the capacity.