Figure 1.
Power control blocks from a control perspective.
Figure 2.
System model of cognitive radio networks.
Figure 3.
Control Block diagram of the CDPC.
Figure 4.
Control Block diagram of the proposed sigmoid power control.
Figure 5.
Random distribution of 30 cognitive users and one primary user.
Table 1.
Cost functions and power control formulas used in the simulation comparison.
Figure 6.
Comparison of power update for a range of channel status.
Figure 7.
Performance comparison of proposed sigmoid algorithm and other algorithms for 30 CRs.
Table 2.
Numerical results obtained from the simulation.
Figure 8.
Comparison of average power for 30 CRs.
Figure 9.
Comparison of average SIR of 30 CRs.
Figure 10.
Performance comparison of average power and SIR for 25 CRs for a range of noise values.