Cognitive cooperative networks with decode-and-forward relay selection under interference constraints of multiple primary users

• Published in: Wireless communications and mobile computing Vol. 15; no. 10; pp. 1433 - 1443
• Main Authors: Tran, Hung, Zepernick, Hans-Jürgen, Phan, Hoc
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2015; John Wiley & Sons, Inc
• Subjects: Cognitive cooperative radio networks; Exact solutions; Interference; Mathematical analysis; Mathematical models; Multiple primary users; Networks; Peak interference power constraint; Relay; Spectrum sharing; Symbols; Transmitters
• ISSN: 1530-8669; 1530-8677; 1530-8677
• DOI: 10.1002/wcm.2419

In this paper, we study the performance of cognitive cooperative radio networks under the peak interference power constraints of multiple primary users (PUs). In particular, we consider a system model where the secondary user communication is assisted by multiple secondary relays (SRs) that operate in the decode‐and‐forward mode to relay the signal from a secondary transmitter to a secondary receiver. Moreover, we assume that the transmit powers of the secondary transmitter and the SRs are subject to the peak interference power constraints of multiple PUs that operate in their coverage range. Given this system setting, we first derive the cumulative distribution function of the instantaneous end‐to‐end signal‐to‐noise ratio. Then, we obtain a closed‐form expression for the outage probability and an exact expression for the symbol error probability of the considered network. These tractable formulas enable us to examine the impact of the presence of multiple PUs on the performance of the considered spectrum sharing system. Furthermore, our numerical results show that system performance is improved significantly when the number of SRs increases or the channel mean power from the secondary user to the PUs is low. Also, any increase in the number of PUs in the coverage range of the secondary transmitter or the SRs leads to degradation in system performance. Finally, Monte Carlo simulations are provided to verify the correctness of our analytical results. Copyright © 2013 John Wiley & Sons, Ltd. In this paper, we study the performance of cognitive cooperative radio networks under the peak interference power constraints of multiple primary users. The cumulative distribution function of the instantaneous end‐to‐end signal to‐noise ratio, a closed‐form expression for the outage probability, and an exact expression for the symbol error probability of the considered network are derived. These tractable formulas enable us to examine the impact of the presence of multiple primary users on the performance of the considered spectrum sharing system.