Dual-Purpose Spectrum Sensor Using IEEE802.15.4a UWB PHY and Energy Detection

Cognitive radio(CR) has become an enabling tech- nology to realize dynamic spectrum access through its spectrum sensing and reconfigurable capability. Robust and reliable spec- trum sensing is needed to discover spectrum opportunity. Single cognitive radios often fail to provide such reliable information due to their inherent sensitivity limitation. Primary signals that are subject to detection by cognitive radios may become weak due to several factors such as fading and shadowing. One approach to alleviate this problem is to perform the spectrum sensing by using multiple CRs or multiple spectrum sensors. This approach known as distributed sensing because sensing is carried out through cooperation of spatially distributed sensors. In distributed sensing, sensors should perform spectrum sensing and forward the result to a destination where data fusion is carried out. In this paper we introduce a concept of a dual-purpose spectrum sensor that can combine the sensing and communication functions. The dual-purpose sensor reuses its detection hardware for both functions resulting in a less hardware complexity. We consider IEEE802.15.4a UWB PHY for communication and energy detection for spectrum sensing. Index Terms—Cognitive radio, spectrum sensing, energy de- tection, ultra-wideband, dual-purpose spectrum sensor