An Adaptive Interference-Avoiding System for DS-UWB Cognitive Radio

This paper addresses the problem of interfering with narrowband licensed users caused by DS-UWB systems. Deducting the colliding frequency band from UWB spectrum, and then employing orthonormal expansion by Hermite-Gaussian functions, the paper develops a low-complexity algorithm for generating DS-UWB signals that adaptively avoid or recover arbitrary colliding bands. A system implementing this algorithm is suggested. Performance comparison with matured seventh Gaussian derivative shows that our system achieves about 1.5dB signal-to-noise gain and 52.2dB signal-to-interference gain over the referenced system in AWGN environment.