Power-rate control with directional transmission and reception in a cognitive radio network

We study the benefits that antenna directivity and power control can bring to a cognitive radio ad hoc network, in terms of concurrent transmission probability, throughput and energy efficiency. The proposed strategies adequately adjust antenna beam pattern and the transmit power of the secondary users to increase the spectrum reuse while respecting a given constraint on the achievable primary rate. Two power control strategies are described: Rate-Efficient Power Control with Directional Transmission and Reception to maximize the secondary channel rate, and Energy-Efficient Power Control with Directional Transmission and Reception to maximize the energy efficiency of the secondary link. Numerical results show that the proposed schemes increase the concurrent transmission probability and that it is possible to increase the average rate and save energy with a lower cost than that of other proposals.