Analytical outage performance of cognitive small cell network

Spectral efficiency (SE) and energy efficiency (EE) are the critical challenges for the next generation cellular network (NGCN). Small cells deployment and cognitive radio which facilitates efficient utilization of radio spectrum are the promising techniques for evolution of the NGCN. In a heterogeneous cellular network (HCN) design where interference is an important issue, outage probability is a fundamental performance measure. In this paper, stochastic geometry based model is used for deriving the outage probability for different resource allocation strategies, which are both interference and instantaneous signal power limited. This paper considers a cognitive based two tier HCN where the macro base stations (MBSs) and cognitive pico base stations (CPBSs) are distributed by two independent homogeneous spatial Poisson point processes (HSPPPs). Co-channel resource allocation strategy considers cross-tier and co-tier interference, while orthogonal channel strategy considers only co-tier interference to calculate the outage probability. Moreover, depending on the outage probability expression, the area spectral efficiency (ASE) and EE are calculated for co-channel and orthogonal channel deployment. Analytical results, with a constraint on minimum instantaneous signal power, show that the outage performance and EE are better for orthogonal resource allocation compare to the co-channel resource allocation strategy.