Clustered network coordinated beamforming for cooperative spectrum sharing of multiple secondary systems

• Authors: V. Rakovic;V. Atanasovski;L. Gavrilovska
• Venue: Proceedings of the 4th International Conference on Cognitive Radio and Advanced Spectrum Management
• Year: 2011

One of the key challenges in cognitive radio is the problem of spectrum sharing. All sharing techniques proposed in the literature try to utilize the spectrum in the most efficient way, but they either lack on computational simplicity or on spectral efficiency. Network MIMO can be seen as a very promising method for spectrum sharing, because it enables multiple systems to use the same spectrum simultaneously, but requires high processing power. This paper proposes a novel cooperative technique for spectrum sharing between multiple secondary cognitive radio systems. The method, named Network Coordinated Beamforming with user Clustering (NCBC), is based on Network MIMO and utilizes Network Coordinated Beamforming (NCBF) and User Clustering (UC). The proposed NCBC approach decreases the computational complexity of NCBF making it suitable for real time spectrum sharing in cognitive radio. Monte Carlo simulations are carried out to examine the performance of the proposed technique in terms of Signal to Interference Ratio (SIR) and channel correlation. The results depict the superior performance of NCBC compared to a simple Frequency Division Spectrum Sharing (FDSS) technique in terms of aggregate system capacity and sum rate.