Underlay cognitive relay networks with imperfect channel state information and multiple primary receivers. Issue 4 (1st March 2015)

• Record Type: Journal Article
• Authors: Huang, Haiyan; Li, Zan; Si, Jiangbo; Guan, Lei
• Is Part Of: IET communications. Volume 9:Issue 4(2015)
• Page Start: 460
• Page End: 467
• Publication Date: 2015-03-01
• Subjects: relay networks (telecommunication) -- cognitive radio -- wireless channels -- radio receivers -- radiofrequency interference -- decode and forward communication -- probability; underlay cognitive relay networks -- imperfect channel state information -- multiple primary receivers -- PU -- multiple proactive partial decode‐and‐forward relays -- relay selection channels -- interference channels -- instantaneous CSI -- outage probability -- interference probability -- IP -- secondary user -- SU -- adaptive power control scheme; Telecommunication systems -- Periodicals; Speech processing systems -- Periodicals; 621.38205
• DOI: 10.1049/iet-com.2014.0429
• Languages: English
• ISSNs: 1751-8628

Abstract

Abstract : In this study, the authors investigate the effect of imperfect channel state information (CSI) on underlay cognitive radio networks in the presence of multiple primary users (PUs). Particularly, with multiple proactive partial decode‐and‐forward (DF) relays available, both the relay selection channels and interference channels are assumed to be imperfect. In this context, firstly, based on the instantaneous CSI (ICSI) of interference channels, exact closed form expressions for the outage probability (OP) and the interference probability (IP) are derived, where IP is used as a performance metric to quantify the impact of harmful interference caused by secondary user (SU) on PUs. It is shown that, when the ICSI of interference channels are imperfect, the secondary networks always interfere with PUs' communications. Then, to reduce the harmful interference caused by secondary nodes, we propose an adaptive power control scheme relying on the partial CSI (PCSI) of interference channels. Finally, simulation results verify the accuracy and effectiveness of the author's analytical study, and indicate the proposed scheme strikes a good tradeoff between the interference introduced by secondary nodes on PUs and SU's performance.