Research For Key Technologies Of WLAN In Dense Deployment Scenario

With the rapid development of information technology,wireless communication has become inseparable from our daily life.Wireless local area networks are widely used in schools,hotels,airports and other crowded places due to the convenient deployment and low cost.However,serious interference would be caused by dense deployed WLAN devices,and further lead to sharp decline in network performance.IEEE 802.11 Working Group is working on the next generation WLAN technology standard-IEEE 802.11 ax to enhance the user experience of intensive scenarios.In order to deal with serious interference caused by dense deployment,a method of uplink Co MP is proposed to enhance the signal quality to improve network performance.In addition,the technologies of channel bonding and downlink OFDMA in intensive scenarios are also studied,and a corresponding simulation platform on the NS3 software is built.It's significant to get information efficiently in wireless local area networks.However,channel interference,especially in the dense deployment of OBSS environment,deteriorates the signal quality seriously.In order to solve the problem of interference in dense deployment,a method of uplink Co MP is proposed.Besides,a specific implementation and the functional simulation is studied to support the proposed method.With the method,the cooperative AP stores and forwards the received data to enhance the signal,which can effectively improve the network performance.In the implementation of the Co MP method,the target AP and the cooperative AP reply ACK to STA after receiving the data.At the same time,the receiving process is optimized by shielding the unwanted signal,which can further improve the system throughput.Ultimately,two tests of typical dense deployment in the simulation implementation demonstrate the superiority of the proposed method.Channel bonding is one of the key technology in 802.11 ac standard.A single STA uses more than two channels to transfer data in order to improve channel utilization.Comparing with the channel bonding technology,the OFDMA technology proposed in 802.11 ax proposal can achieve multiple access,which can improve the efficiency of data transmission and enhance the user experience significantly.In order to realize the function of channel bonding,a multichannel transmission mechanism based on NS3 is designed in this paper.The validity of the simulation platform is proved by comparing with the theoretical throughput.Furthermore, on the basis of the channel bonding simulation platform,a multi-user access scheme of the downlink OFDMA is studied,which points out that the data is modulated with different subcarriers for parallel transmission.Finally,the construction and verification of the downlink OFDMA platform is completed.