Spectrum sensing in MB-OFDM based cognitive UWB systems coexistence with WiMax

Cognitive UWB systems have been developed into a promising solution for more efficient spectrum resource usage. Due to the broad bandwidth of operation, cognitive UWB systems have to coexist with other radio systems that occupy the same bandwidths. MB-OFDM technology is adopted in UWB physical layer since it has an inherent ability to offer better coexistence. Spectrum sensing has been identified as a key function to ensure mutual friendly coexistence. This paper explores the issues in coexistence between cognitive UWB systems and WiMax. A spectrum sensing algorithm based on the Neyman-Person criterion is proposed. The estimator-correlator is theoretically derived and reduced to the energy detector for practical application. The performance results indicate that the MB-OFDM receiver based on energy detector will enable robust detection of the WiMax uplink signal.