Compensation of link distortion for cognitive WPMCM UWB system

Cognitive radio performs efficient utilization of available communication resources. Cognitive ultra wideband (UWB) system is a tempting candidate for short range and high data rate communication with low cost, and low power consumption. Wavelet packet based multicarrier modulation (WPMCM) UWB has inherent potential to fulfill cognitive radio requirements. In this research, we survey the literature on cognitive radio sensing mechanism in the presence of distortion and propose a novel link effect compensation accompanied by power loading, to mitigate the effects of interference from primary signal. Wavelet transform is used for spectrum sensing, and Lagrange multiplier applied for power allocation to minimize the bit error rate at the receiver. System performance is investigated by MATLAB to compare the system under different UWB channel models.