Joint optimization of detection thresholds and power allocation in OFDM based cognitive femtocell networks

Spectrum sensing in cognitive femtocells play an important role in detecting spectrum holes and to opportunistically use under-utilized frequency bands without causing harmful interference to macrocell users. In case of mass deployment of femtocells, interference management is essential to maximize the capacity and achievable data rates. In this paper, a novel algorithm is proposed, based on Lagrangian dual decomposition technique, for jointly optimizing the detection threshold and power allocation to maximize the total aggregated opportunistic throughput per unit bandwidth of a co-channel OFDM based femtocell network, densely deployed over a macrocell architecture, under a constraint of the total interference generated towards macrocell users. Simulation results show that the proposed algorithm is stable, attains convergence and achieves considerable rate gain.

[1]  Kwang-Cheng Chen,et al.  Downlink capacity of two-tier cognitive femto networks , 2010, 21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[2]  W. Marsden.  I and J , 2012 .

[3]  Jie Zhang,et al.  Access control mechanisms for femtocells , 2010, IEEE Communications Magazine.

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

[5]  Iti Saha Misra,et al.  Collaborative spectrum sensing in real cognitive radio network , 2013, 2013 International Conference on Advances in Computing, Communications and Informatics (ICACCI).

[6]  Sergio Barbarossa,et al.  Joint optimization of detection thresholds and power allocation for opportunistic access in multicarrier cognitive radio networks , 2009, 2009 3rd IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP).

[7]  Lan Wang,et al.  Mobility Management Schemes at Radio Network Layer for LTE Femtocells , 2009, VTC Spring 2009 - IEEE 69th Vehicular Technology Conference.

[8]  Jie Zhang,et al.  Interference avoidance and dynamic frequency planning for WiMAX femtocells networks , 2008, 2008 11th IEEE Singapore International Conference on Communication Systems.

[9]  Jianmin Zhang,et al.  Optimal Distributed Subchannel, Rate and Power Allocation Algorithm in OFDM-Based Two-Tier Femtocell Networks , 2010, 2010 IEEE 71st Vehicular Technology Conference.

[10]  Jeffrey G. Andrews,et al.  Femtocell networks: a survey , 2008, IEEE Communications Magazine.

[11]  Yan Zhang,et al.  Downlink Spectrum Sharing for Cognitive Radio Femtocell Networks , 2010, IEEE Systems Journal.

[12]  Jeffrey G. Andrews,et al.  Power control in two-tier femtocell networks , 2008, IEEE Transactions on Wireless Communications.

[13]  Bang Chul Jung,et al.  Opportunistic Underlay Transmission in Multi-Carrier Cognitive Radio Systems , 2009, 2009 IEEE Wireless Communications and Networking Conference.

[14]  Rentsen Enkhbat,et al.  Joint Power Control, Base Station Assignment, and Channel Assignment in Cognitive Femtocell Networks , 2010, EURASIP J. Wirel. Commun. Netw..