A novel energy efficiency (EE)-oriented cognitive spectrum sharing scheme in heterogeneous cognitive radio networks, called energy-efficient cognitive cooperation (ECC) is proposed, in which the primary system release...
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A novel energy efficiency (EE)-oriented cognitive spectrum sharing scheme in heterogeneous cognitive radio networks, called energy-efficient cognitive cooperation (ECC) is proposed, in which the primary system release a part of its radio spectrum to the secondary system in exchange for secondary user (SU) served as a relay to assist the transmission of the primary user (PU) traffic. On the basis of ECC scheme, an EE maximisation non-convex problem for SUs is formulated under the circuit power consumption and the QoS requirements as well as power constraints. By virtue of parametricdinkelbach's algorithm and golden section search method, an efficient resource allocation algorithm is developed. Simulation results show that our proposals attain significantly higher EE compared with the non-cooperation transmission without sacrificing the performance of PU's QoS, and thus, a 'win-win' situation is achieved.
In this paper, a full-duplex (FD) transmitter cooperative scheme is proposed to improve the achievable rate for multiple access channels (MACs). In the proposed scheme, by leveraging the FD amplify-and-forward (AF) pr...
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In this paper, a full-duplex (FD) transmitter cooperative scheme is proposed to improve the achievable rate for multiple access channels (MACs). In the proposed scheme, by leveraging the FD amplify-and-forward (AF) protocol, two FD transmitters send their own signals and forward the received signals from their counterparts to the receiver, which adopts both the forward and backward decoding schemes to decode the source messages. First, the analyses of the equivalent channel model and the statistics of the accumulated additive white Gaussian noise and residual self-interference (ANRI) caused by imperfect self-interference cancellation are performed. Then, the achievable rate regions are obtained by utilizing both the forward and backward decoding schemes, and a two-stage iterative algorithm is proposed to characterize these regions: in each iteration, the covariance matrix of the ANRI is first updated;then, for the fixed covariance matrix of the ANRI, the transmission parameters of the two transmitters are calculated by a two-step iterative algorithm based on the parametric dinkelbach algorithm, sequential convex programming (SCP), and semidefinite relaxation (SDR). The numerical results show that the proposed scheme outperforms the half-duplex cooperative scheme and conventional MAC scheme without cooperations when the channels between the two transmitters are in good condition.
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