This code is for the paper "Particle Swarm Optimization for Interference-Limited Unmanned Aerial Vehicle-Assisted Networks", which is an extension for "3-D Placement of UAVs Based on SIR-Measured PSO Algorithm". It is disordered since I don't have time to reorganize the codes. The main author of these codes is Wentao Liu. If you have any question, please contact with him. Email: wentaoliu1@link.cuhk.edu.cn