Interference analysis of cognitive radio networks

In spite of spectrum sensing, aggregate interference from cognitive radios (CRs) remains as a deterring factor to the realization of spectrum sharing. We provide a systematic approach of evaluating the aggregate interference (I-aggr) experienced at a victim primary receiver. In our approach, we model the received power versus propagation distance relations between a primary transmitter, primary receiver, and CRs. Our analytical framework differs from the previous works in that we have formulated the relationship between I-aggr and the sensing inaccuracy of CRs. Energy detector is assumed for the purpose of spectrum sensing. I-aggr is expressed explicitly as a function of the number of energy samples collected (N) and the threshold signal-to-noise ratio level used for comparison (SNR epsilon). The theoretical analysis is then applied to a practical scenario of spectrum sharing between digital TV broadcast and the IEEE 802.22 wireless regional area network systems. The impact on digital TV reception is evaluated in terms of signal-to-interference ratio. The proposed method allows us to determine the appropriate wireless regional area network operating conditions that fulfill the signal-to-interference ratio requirement imposed by regulator. Copyright (C) 2016 John Wiley & Sons, Ltd.