Fig. 5

Impact of varying the number of spectrum sharing operators on achieved system throughput. For simplicity, we have assumed \(\protect \phantom {\dot {i}\!}\rho _{1}=\rho _{2}=\cdots =\rho _{N_{\text {op}}}\) with N _sub=512. Each operator transmits its signal with 4 W, irrespective of the number of subcarriers it is assigned with. When there is increase in the number of operators, there is linear increase in the total transit power \(\sum _{n=1}^{N_{\text {op}}}P_{\text {Max}}^{(n)}\). For example, (i) N _op=2, total power is 8 W, and (ii) N _op=6, total transmission power in the shared spectrum access system is 24 W, regardless of the fact that the number of subcarriers \(||\mathcal {S}_{\text {grid}}||\) remains the same