Evaluation and mitigation of co-channel interference in mobile WiMAX 802.16e downlink

The performance of WiMAX (Worldwide Interoperability for Microwave Access) system is significantly limited by the co-channel interference (CCI) signals which are transmitted from other cellular cells. Thus, the co-channel interference becomes a major performance limiting factor and has to be accounted in designing WiMAX networks. This research focuses on evaluating the CCI in terms of the Signal-to-Interference-and-Noise-Ratio (SINR) for mobile WiMAX system, as well evaluating the performance of equalization process at the receiver side by using Mean Square Error- Successive Interference Cancellation (MMSE-SIC) technique to mitigate the CCI problem in mobile WiMAX downlink and in various propagation environments. Our results showed that the downlink performance is significantly improved by using the proposed MMSE-SIC technique. For SINR of 10 dB at the mobile station, the results showed an improvement of 1% in the BER (Bit Error Rate) for all propagation environments.