Concurrent Conmmunication Technology In Enterprise WLAN

In the modern enterprise WLAN,Wireless access points deployed densely so that adjacent co-channel network situation become more and more prevalent.The use of the same channel makes each node in the network channel competitive seriously and makes single node transmission efficiency decline sharply,which affect seriously the transmission performance of the entire network.In order to improve the effective performance of communication transmission,multi-node concurrent communication technology has become a hot research topic.Now multi-node concurrent communication technology mainly focus on the joint synchronous operation of access points,forming a large distributed multi-antenna systems.This requires a high synchronization accuracy,and it can only achieve concurrent uplink or downlink concurrent communication at same time.In the actual scene,the situation that uplink and downlink communicate conconcurrently has been widespread,but the uplink and downlink concurrent communication technology is the lack of research.Based on System Model assumed by the actual scenario,This Paper makes use of the advantage of central controller to realize concurrent communications,and uses interference nulling techniques and cooperative interference cancellation technology to solve the client and the AP-side interference repectively caused by the concurrent communication.This paper implemented the concurrency control mechanism,interference nulling and cooperative interference cancellation technology on USRP/GNU Radio software radio respectively.The results of experiment demonstrated that the rate of change of CSI is stable within a certain number,which implied that CSI can be used for interference nulling technology and collaborative interference cancellation technology.Besides,The implementations of concurrency control mechanism,interference nulling and collaborative interference cancellation technology verified the feasibility of this concurrent communication technology;This concurrent communication technology can be a additional communication mechainism as the existing distributed channel access communication mechanism,which can be triggered when conditions are met and it can improve the overall network throughput.