Optimal power allocation for bi‐directional full duplex underlay cognitive radio networks

Abstract

Cognitive radio and full duplex transmissions are regarded as two effective techniques to improve the spectral efficiency. By combining the two promising techniques, the problem of power allocation for bi‐directional full duplex underlay cognitive spectrum sharing is studied. To protect the primary transmission, consider both the instantaneous and statistical channel state information to adjust the transmit powers of secondary users to avoid causing intolerable interference to the primary users. The corresponding quality‐of‐service (QoS) constraints are determined for the primary system. On this basis, propose optimal power allocation schemes to facilitate the secondary transmission while guaranteeing the primary QoS constraint. Simulation results are provided to verify the efficiency of proposed schemes in improving the system capacity.