Algorithm 1 An iterative algorithm for solving Problems (P1) and (P2)

1:Initialize power allocation $\{p_{kr}^{\left(i\right)}\left[n\right],p_{rd}^{\left(i\right)}\left[n\right]\}$ and UAV trajectory $\left\{{\mathbf{q}}^{\left(i\right)}\left[n\right]\right\}$, slack variables $\left\{u_k^{\left(i\right)}\left[n\right]\right\}$, $\left\{u_d^{\left(i\right)}\left[n\right]\right\}$. Set iteration $i=0$, the precision $\epsilon >0$. 2: repeat 3:    Solve subproblem (P1.1) with $\{p_{kr}^{\left(i\right)}\left[n\right],p_{rd}^{\left(i\right)}\left[n\right]\}$ and $\left\{{\mathbf{q}}^{\left(i\right)}\left[n\right]\right\}$, obtain the optimized result denoted by $\left\{{\tau }_k^{(i+1)}\left[n\right]\right\}$. 4:    Solve subproblem (P1.2.1) with $\left\{{\tau }_k^{(i+1)}\left[n\right]\right\}$ and $\left\{{\mathbf{q}}^{\left(i\right)}\left[n\right]\right\}$, obtain the optimized result denoted by $\{p_{kr}^{(i+1)}\left[n\right],p_{rd}^{(i+1)}\left[n\right]\}$. 5:    Solve subproblem (P1.3.2) with $\left\{{\mathbf{q}}^{\left(i\right)}\left[n\right]\right\}$, $\left\{{\tau }_k^{(i+1)}\left[n\right]\right\}$ and $\{p_{kr}^{(i+1)}\left[n\right],p_{rd}^{(i+1)}\left[n\right]\}$ as well as $\{u_k^{\left(i\right)}\left[n\right],u_d^{\left(i\right)}\left[n\right]\}$, obtain the optimized result denoted by $\{{\mathbf{q}}^{(i+1)}\left[n\right],u_k^{(i+1)}\left[n\right],u_d^{(i+1)}\left[n\right]\}$. 6:    Update $i=i+1$. 7: until 8:    The algorithm converges to $\epsilon$.