Sensing-based opportunistic channel access
Mobile Networks and Applications
Robust beamforming in cognitive radio
IEEE Transactions on Wireless Communications
A recursive least squares implementation for LCMP beamforming underquadratic constraint
IEEE Transactions on Signal Processing
IEEE Transactions on Wireless Communications - Part 1
Cognitive radio: brain-empowered wireless communications
IEEE Journal on Selected Areas in Communications
| Hi-index | 0.00 |
In this paper, we propose an adaptive non-intrusive cognitive radio network based on smart antenna technologies. The cognitive transmitter (CT), which is equipped with antenna array, first estimates and tracks the composite steering vectors of each primary (licensed) user. In what follows, CT forms transmit beamforming to place nulls to primary receivers based on the estimated spatial signatures. Moreover, we extensively analyze performance degradation caused by spatial signatures mismatch (estimation error) and verify that the proposed robust nulls-steering beamformer can comprehensively alleviate the mismatch effect. Simulation results demonstrate convergence of the proposed gradient-based recursive least squares algorithm. Furthermore, we have shown that outage probability can be kept extremely low under appropriate array size, which ensures the practicability of the proposed scheme.