Performance Optimization in UAV-Assisted Wireless Powered mmWave Networks for Emergency Communications

Algorithm 2

Beam alignment and first-charging-then-receiving.

Run at the UAV

Input: , , , , , , , ,

Output: , , ,

1: Initialize to 0

2: Broadcasts a directional beacon frame in the mmWave beam facing the ground during the starting slot

3: Waiting for response frames during the response slots

4: Broadcasts a confirmation frame to announce the conflict-free UEs during the confirming slot

5: Observe the number of conflict-free UEs

6: Update with the number of the current conflict-free UEs

7: Observe the number of response slots with conflicting signal

8: Update with the number of conflicting response slots

9:

10:

11: For each UE do

12:  Calculate according to formula (11)

13:  IfthenEnd If

14: End for

15: Ifthen

16:  Update the UAV’s beam width according to

17: End If

18: Get by invoking Algorithms1–2 in [43]

19: Calculate according to formula (16)

20:

21: Return , , ,