Markov Chain Existence and Hidden Markov Models in Spectrum Sensing

—The primary function of a cognitive radio is to detect idle frequencies or sub-bands, not used by the primary users (PUs), and allocate these frequencies to secondary users. The state of the sub-band at any time point is either free (unoccupied by a PU) or busy (occupied by a PU). The states of a sub-band are monitored over L consecutive time periods, where each period is of a given time interval. Existing research assume the presence of a Markov chain for sub-band utilization by PUs over time, but this assumption has not been validated. Therefore, in this paper we validate existence of a Markov chain for subband utilization using real-time measurements collected in the paging band (928-948 MHz). Furthermore, since the detection of idle sub-bands by a cognitive radio is prone to errors, we probabilistically model the errors and then formulate a spectrum sensing paradigm as a Hidden Markov model that predicts the true states of a sub-band. The accuracy of our proposed method in predi...

• Type: Conference
• Year: 2009
• Where: PERCOM
• Authors: Chittabrata Ghosh, Carlos de M. Cordeiro, Dharma P. Agrawal, M. Bhaskara Rao
• Keywords: Cognitive Radio, Consecutive Time Periods, Markov Chain, PERCOM 2009, Wireless Networks