Cognitive radio-based framework and self-optimizing temporal-spectrum block scheduling for QoS provisioning in WiMAX

Cognitive radio (CR) is seen as a solution to the current low-usage of the radio spectrum and the problem of the fixed spectrum allocation. Quality of service (QoS) provisioning is an important issue in the deployment of broadband wireless access networks with real-time and non-real-time traffic integration in wireless spectrum. The connection-level and packet-level scheduling scheme is essential to guarantee the QoS requirements of different service classes. WiMAX orthogonal frequency division multiple access (OFDMA) system specifies the orthogonal frequency division multiplexing (OFDM) symbol mapping in a rectangular area manner. The rectangular mapping problem is known to be NP-complete. In this paper, we propose a novel Cognitive Radio-based QoS support framework and Cognitive Radio-based Self-optimizing temporal-spectrum block (TSB) scheduling which is a joint sub-carrier allocation and symbol-duration scheduling cum mapping scheme in WiMAX point-to-multipoint (PMP) WirelessHUMAN™ OFDMA systems. The proposed solution can intelligently explore unused spectrums and spread the system to non-active spectrums to significantly improve the capacity of the system and provide guaranteed QoS to real-time traffic. Extensive simulation experiments have been carried out to evaluate the performance of our proposal. The simulation results show that our proposed solution can expand the capacity of the WiMAX system while providing QoS to real-time and non-real-time traffic.