dbspf/wireless_utils.py at dev · hslyu/dbspf · GitHub

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#!/usr/bin/env python3

# Depth first search(DFS) based UAV base station simulation code.
# Author : Hyeonsu Lyu, POSTECH, Korea
# Contact : hslyu4@postech.ac.kr
import random
import math
import time

FREQUENCY = 2.0*1e9 # Hz
LIGHTSPEED = 3*1e8 # m/s
#SURROUNDING_A = 11.95 # Envrionmental parameter for probablistic LOS link
#SURROUNDING_B = 0.136 # Envrionmental parameter for probablistic LOS link
SURROUNDING_A = 9.61 # Envrionmental parameter for probablistic LOS link
SURROUNDING_B = 0.16 # Envrionmental parameter for probablistic LOS link
#LOS_EXCESSIVE = 2.3 # dB, excessive pathloss of los link
#NLOS_EXCESSIVE = 34 # dB, excessive pathloss of nlos link
LOS_EXCESSIVE = 1 # dB, excessive pathloss of los link
NLOS_EXCESSIVE = 40 # dB, excessive pathloss of nlos link
NOISE_DENSITY = -174

def get_pathloss(distance, altitude):
    """
    Caculate pathloss --> snr --> spectral efficiency
    """
    los_prob = get_los_prob(distance, altitude)
    pathloss = 20*math.log10(4*math.pi*FREQUENCY*distance/LIGHTSPEED) + los_prob*LOS_EXCESSIVE + \
                (1-los_prob)*NLOS_EXCESSIVE
    return pathloss

def get_los_prob(distance, altitude):
    angle = math.pi/2 - math.acos(altitude/distance)
    return 1/(1 + SURROUNDING_A * math.exp(-SURROUNDING_B*(180/math.pi*angle - SURROUNDING_A)))

def psd2snr(pathloss):
    """
    Because unit of psd is 200mW/20MHz, we should convert it to mw/Hz
    """
    psd = 1e-5
    return 10*math.log10(psd) - pathloss - NOISE_DENSITY

def snr2se(snr):
    """
    Because unit of resource is 20MHz,
    we should convert the unit of se from bps/Hz to Mbps/20MHz
    """
    return math.log(1+pow(10,snr/10),2)

if __name__ =="__main__":
#    (get_pathloss(300,100))
#    (get_pathloss(50,50))
    print(f'LoS Prob= {get_los_prob(200, 100):.4f}, {get_pathloss(150,50)=:.4f}, snr={psd2snr(get_pathloss(150,50)):.4f}, se={snr2se(psd2snr(get_pathloss(150,50))):.4f}')
    print(f'LoS Prob= {get_los_prob(150, 100):.4f}, {get_pathloss(100,50)=:.4f}, snr={psd2snr(get_pathloss(100,50)):.4f}, se={snr2se(psd2snr(get_pathloss(100,50))):.4f}')
    print(f'LoS Prob= {get_los_prob(100, 100):.4f}, {get_pathloss(50,50)=:.4f}, snr={psd2snr(get_pathloss(50,50)):.4f}, se={snr2se(psd2snr(get_pathloss(50,50))):.4f}')
#    print(f'{get_pathloss(50,50)=}')
#    print(f'{psd2snr(get_pathloss(150,50))=}')
#    print(f'{psd2snr(get_pathloss(50,50))=}')
#    print(f'{snr2se(psd2snr(get_pathloss(150,50)))=}')
#    print(f'{snr2se(psd2snr(get_pathloss(50,50)))=}')