Adaptive spatial projected spectrum sharing in multi-antenna cognitive radio networks
Rong Me · Electronic Design Engineering · 2015
A spectrum sharing method based on adaptive spatial projection is proposed for central multi-user multi-antenna cognitive radio networks. In order to guarantee the transmission of primary users(PUs)as well as provide transmission opportunities to cognitive users(CUs),signals from cognitive base station(CBS)are adaptively projected onto the sub-spaces of the channel between CBS and PUs to avoid or reduce the interference between two systems according to the variances of spectrum and spatial resource occupancy caused by the random access of PUs. Furthermore, block diagonalization and singular value decomposition of channel matrices are adopted to cancel the interference between CUs. Performance analysis and simulation results show that, compared with existing methods, the proposed method can improve both the achievable sum rate of CUs and the robustness in different load scenarios.