  In a cognitive radio (CR) network, CR users intend to operate over the same
spectrum band licensed to legacy networks. A tradeoff exists between protecting
the communications in legacy networks and maximizing the throughput of CR
transmissions, especially when CR links are unstable due to the mobility of CR
users. Because of the non-zero probability of false detection and
implementation complexity of spectrum sensing, in this paper, we investigate a
sensing-free spectrum sharing scenario for mobile CR ad hoc networks to improve
the frequency reuse by incorporating the location awareness capability in CR
networks. We propose an optimal power control algorithm for the CR transmitter
to maximize the concurrent transmission region of CR users especially in mobile
scenarios. Under the proposed power control algorithm, the mobile CR network
achieves maximized throughput without causing harmful interference to primary
users in the legacy network. Simulation results show that the proposed optimal
power control algorithm outperforms the algorithm with the fixed power policy
in terms of increasing the packet delivery ratio in the network.
