Efficient Spectrum Sensing/monitoring Methods and Testbed Development for Cognitive Radio Based Wsn

In this work, we propose an efficient spectrum sensing technique based on Doubly Cognitive Architecture (DCA) and an efficient spectrum monitoring technique based on partial spectrum sensing. In addition to this, we have developed a one of its kind testbed for Cognitive Radio-based wireless sensor network (CRWSN), where the proposed techniques are successfully implemented and tested. The testbed is equipped with significant features such as user access to realize re-configurability, dynamic spectrum access, user mobility and cooperation between CRWSN nodes. The testbed can serve as a development platform providing insights into CRWSN. Our experiments on the testbed show that DCA is more efficient with average spectrum discovery time (3 sec.) and variance (2.66 sec) reduced to 0.42 and 0.19 times the average normal spectrum sensing (7 sec.) and variance (13.83), respectively. Partial sensing-based spectrum monitoring also outperforms periodic spectrum monitoring with average PU detection time (3 sec.) and variance (1.85) significantly reduced to 0.27 and 0.12 times the average of 11 seconds and variance 15.42 of periodic spectrum monitoring. Timebandwidth-product of partial spectrum monitoring is found to be 50% more than periodic spectrum monitoring leading to higher bandwidth efficiency. Keywords—Cognitive Radio; Wireless Sensor Networks; Spectrum Sensing; GNU Radio; USRP