Joint Subchannel Pairing and Power Control for Cognitive Radio Networks with Amplify-and-Forward Relaying

Table 2

Average running time (in seconds) comparison for the four algorithms when the number of subchannels 𝑁 changes, 𝐷=150 m, 𝛼=0.5,  𝑃_𝑆=𝑃_𝑅=3 W, and 𝑇₁=𝑇₂=0.15 W.

𝑁	Suboptimal algorithm 1	Suboptimal algorithm 2	Optimal algorithm	Optimal algorithm in [8]
6	0.4858	0.3908	1.6993	1.3974
8	0.5162	0.4072	2.6176	2.5733
10	0.5429	0.7631	3.8069	4.1873
14	0.6016	0.4782	7.0885	11.1492
18	0.6654	0.5678	12.1659	24.2083