Outage capacity analysis for SIMO Nakagami-m fading channel in spectrum sharing environment

In this paper, we consider the spectrum sharing cognitive radio system, wherein single-input multiple-output fading channel is assumed. Subject to joint average interference constraint and peak interference constraint of primary user, the outage capacity of cognitive user involving joint beamforming and power control is analyzed. We derive the optimal transmission power and beamforming weights of cognitive user for outage capacity, and the expressions of outage probability for a given outage capacity under the most versatile Nakagami-m fading model are presented. When the Nakagami fading parameter m are integers, the expressions are exhibited in closed-form, which avoid complex numerical integrals. Besides, we also investigate the delay-limited capacity and the zero-outage interference constraint, which are related with zero-outage transmission. Large amount of simulations are conducted to corroborate our theoretical results.