Throughput Maximization in Cooperation Based Symbiotic Cognitive Radio Networks

In the symbiotic cognitive radio (CR) networks, the CR users (CUs) may assist the primary transmission in a cooperation time, and obtain an incentive time for their own data transmission. In this letter, we study the throughput maximization problem in the symbiotic CR networks. Under the symbiosis and transmit power constraints, we aim to find the optimal cooperation time to assist the primary transmission and power allocations among the CUs. Given the cooperation time, the optimal power allocations can be solved by multi-level water-filling (MWF) with individual volume limits. A theoretical analysis is presented on the cooperation time and a modified bisection algorithm with low complexity is proposed to find the sub-optimal cooperation time. Simulation results show that the spectrum usage efficiency can be significantly improved as the number of CUs increases.

[1]  Umberto Spagnolini,et al.  Spectrum Leasing to Cooperating Secondary Ad Hoc Networks , 2008, IEEE Journal on Selected Areas in Communications.

[2]  Aria Nosratinia,et al.  Cooperative communication in wireless networks , 2004, IEEE Communications Magazine.

[3]  Babak Azimi-Sadjadi,et al.  Diversity gain for cooperating nodes in multi-hop wireless networks , 2004, IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004.

[4]  Peng Gong,et al.  Symbiotic Architecture for the Cognitive Radio Networks With Amplify-and-Forward Relaying Cooperation , 2008 .

[5]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[6]  Simon Haykin,et al.  Cognitive radio: brain-empowered wireless communications , 2005, IEEE Journal on Selected Areas in Communications.

[7]  Brian M. Sadler,et al.  A Survey of Dynamic Spectrum Access , 2007, IEEE Signal Processing Magazine.