An Analysis of the Performance in Cognitive Relay Networks Based on a Joint Interference Power Constraints
HUANG Yangchao
CHU Peng
ZHU Rui
MENG Qingwei
Abstract：To guarantee the reliable communications of the primary user (PU)in cognitive relay networks under underlay spectrum sharing constraints,the transmission powers of the secondary source and relays must satisfy the needs of the interference power constraints at the PU receiver.With both peak and average interference power limits,the paper analyzes the performance of selection cooperative decode-and-for-ward (DF)relaying in underlay cognitive relay networks.Particularly,taken the correlations among the received signal to noise ratios (SNRs)of the first hop in the relaying transmission caused by interference power constraint imposed by the primary receiver into account,the paper derives exact closed-form ex-pressions for the outage probability and channel capacity of the secondary user (SU)under condition of Rayleigh fading channels.The simulation results show that the analytical outcomes of the outage probabili-ty and channel capacity match well with the simulation results,the performance of the SU is degraded due to the dependence of the links between the SU source and the PU receiver in the context of cognitive radio environment with spectrum sharing constraints.Importantly,the consideration of the correlations im-proves the system performance as much as 2 dB.
Keywords：cognitive relay networksspectrum sharingRayleigh fadingoutage probabilitychannel ca-pacity
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 76-82 )