路径损耗对802.11无线局域网干扰与载波监听性能的影响研究

摘要

分析了路径损耗因子对802.11无线局域网的干扰与载波监听性能的影响,揭示了增大路径损耗因子的优势.基于SNR阈值模型和固定的载波监听阈值,分析了802.11a/b/g的主要比特速率.首先,在绝大多数的比特速率下(除比特速率为1和2Mbps外),增大路径损耗因子有利于增加SIR和减小干扰半径,这有助于提高比特速率和空间复用.其次,基于蜂窝网络拓扑指出了最优网络容量随路径损耗因子的增大而增大.最后,图例分析和仿真实验揭示了增大路径损耗因子有助于改善载波监听的准确率.城市中由于建筑物和人口稠密会增大路径损耗因子,因此可提升无线局域网的性能.%We analyzed how path loss exponent affects the interference and carrier sensing performance of 802.11 WLANs and revealed the advantages of larger path loss exponent.This work is based on the SNR threshold reception model and fixed carrier sensing thresholds,and the main bit rates of 802.11a/b/g are considered.Firstly,increasing path loss exponent increases SIR and decreases interference range.Secondly,the optimal network capacity increases with the path loss exponent.Thirdly,analysis and simulation reveal that larger path loss exponent results in larger carrier sensing accuracy.The performance of WLANs improves in cities because dense buildings and population increase path loss exponent.