Noncoherent ultra wideband wireless sensor networks for primary user detection

As a result of increasing demand for new technologies, unlicensed usage of available spectrum has become very essential to provide an efficient usage of spectrum. For that reason, sensor networks may be a reliable option to decide on the absence/presence of licensed users and to communicate without causing much interference as a secondary user network. These networks consist of two communication links for primary user detection. One link is between the primary user and the sensors, and the other link is between the sensors and the fusion center. In this study, we consider an IEEE 802.15.4a based ultra wideband (UWB) network with a noncoherent receiver structure for the first link. For the second link binary pulse position modulation is implemented to convey primary user information to the fusion center. Numerical expressions for probabilities of false alarm and detection for the overall system are obtained and validated by simulations, where the performance of the system improves with number of sensors and the reliability of the first link. The results obtained from this study can be used for improving the primary user detection performance of UWB based wireless sensor networks in noncoherent operation mode.