Power and Rate Control with Dynamic Programming for Cognitive Radios

Power and rate control schemes for a single cognitive radio (CR) channel are considered in the presence of licensed primary radios (PRs). A dynamic programming (DP) based algorithm is proposed to maximize the long-term average rate for the CR link under constraints on the total energy budget and the CR-to-PR disturbance. In the proposed algorithm, the behavior of PRs is modeled as a two-state Markov chain. Based on such a model, the optimal power and rate control strategy for each time slot is derived, which is a function of the energy level at the beginning of current time slot and the previous behavior of PRs. Simulation results show that the proposed algorithm can lead to a significant performance improvement in term of the long-term average rate while keeping the probability of CR-to- PR disturbance below a given level.

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

[2]  Ying-Chang Liang,et al.  A Two-Phase Channel and Power Allocation Scheme for Cognitive Radio Networks , 2006, 2006 IEEE 17th International Symposium on Personal, Indoor and Mobile Radio Communications.

[3]  Eytan Modiano,et al.  Optimal transmission scheduling over a fading channel with energy and deadline constraints , 2006, IEEE Transactions on Wireless Communications.

[4]  Fan Zhang,et al.  Improving communication energy efficiency in wireless networks powered by Renewable energy sources , 2005, IEEE Transactions on Vehicular Technology.

[5]  Eytan Modiano,et al.  Optimal energy allocation and admission control for communications satellites , 2003, TNET.

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

[7]  N. Hoven,et al.  Power scaling for cognitive radio , 2005, 2005 International Conference on Wireless Networks, Communications and Mobile Computing.

[8]  Dimitri P. Bertsekas,et al.  Dynamic Programming and Optimal Control, Two Volume Set , 1995 .

[9]  Ian F. Akyildiz,et al.  NeXt generation/dynamic spectrum access/cognitive radio wireless networks: A survey , 2006, Comput. Networks.

[10]  Ananthram Swami,et al.  Decentralized cognitive MAC for opportunistic spectrum access in ad hoc networks: A POMDP framework , 2007, IEEE Journal on Selected Areas in Communications.

[11]  Shlomo Shamai,et al.  Optimal Power and Rate Control for Minimal Average Delay: The Single-User Case , 2006, IEEE Transactions on Information Theory.