Secure beamforming method for artificial‐noise‐aided multiuser broadcast system with users of different importance under secrecy outage probability constraint

Robust transmission design for artificial noise aided multiuser broadcast system in inaccurate channel state information scenario with users of different importance

“…Moreover, we would compare our new robust method with the BF design method which does not consider inaccurate CSI in [36]. We would also show the influence on performance by system parameters, and try to explain why these influences occur.…”

“…In the simulation procedure, we suppose a multiuser system with three users ($$K = 3$$), and regard user‐1 as the main user, user‐2 and user‐3 as the common users. The AN generating method for algorithms in [34–36] are all classic 'null‐space' methods proposed in former articles as [7–9]. And for convenience, we set $$\sigma _s^2 = \sigma _r^2 = 1$$, $$\sigma _e^2 = {10^{ - 4}}$$, namely $${\varphi _1} = {\rm{}}1$$, $${\varphi _3} = {10^{ - 4}}$$, and $${P_{tx}} = 10$$.…”

“…As the norm of H is 1 in all simulations, $${\psi _b} = 0.1$$ means a 10% channel estimation error. We use the BF method in [36] as the control group, and the result is shown in Figure 3. In this simulation, we set SOP constraint parameters as $${\varepsilon _1} = {\rm{}}0.05$$ and $${\varepsilon _2} = {\rm{}}0.1$$.…”

“…Moreover, we set$${\rm{}}{M_T} = {\rm{}}16$$. We can see that in an inaccurate CSI scenario, our new algorithm obviously plays a better performance in secrecy capacity than the BF method in [36], both for main users and common users. Moreover, we can see that for both the new robust method and algorithm in [36], the secrecy capacity of user‐1 ascends quickly with the increase of the average SNR, while the secrecy capacity of common users almost keeps constant.…”

“…Comparison of new robust algorithm and BF method in [36] for secrecy capacity $${C_{se{c_k}}}$$ for different users versus different average SNR $${\bar \gamma _{{B_k}}}$$( $${\varepsilon _1} = 0.05$$, $${\varepsilon _2} = 0.1$$, $${\gamma _1} = 12{\rm{dB}}$$, $${\gamma _2} = 6{\rm{dB}}$$,$${M_T} = 16,$$$${\psi _b} = 0.1$$)…”