Co-channel interference mitigation technique for mobile WiMAX downlink system deployed via Stratospheric Platform

This paper aim at evaluating an interference mitigation technique proposed for Stratospheric Platform (SPF) WiMAX downlink system. Performance evaluation of mobile WiMAX system under impact of co-channels interfering from the SPF antennas operating in the same frequency band is proposed to be studied in this paper. Several frequency reuse pattern are simulated to find the best reuse pattern which means that they have a minimum interference level. Simulation results clearly demonstrate that the co-channel interference was dominant when delivering mobile WiMAX via SPF and its performance can be effectively improved using frequency reuse patterns. Results relative to co-channel interfering evaluation, showed an improvement on the system performance with increasing frequency reuse pattern (from 1 to 3, or from 3 to 4). The remaining results with respect to BER simulation indicate how K Rice factor which is governed by elevation angle, Doppler shifts due to mobility, and physical layer setting of broadband system can contribute to the overall performance. Finally, simulation results clarified that applying spatial diversity at transmitter side can improve the performance at low elevation angles.