| In recent years,with the rapid development of short-distance communication technology,wireless local area network has been widely popularized due to its advantages of easy deployment,easy expansion,and low cost,and has been integrated into every corner of people’s daily life,greatly improving the convenience of daily production and life.However,with the rapid development of emerging technology industries and the continuous emergence of new application scenarios such as augmented reality,Internet of Vehicles,unmanned driving,and remote surgery,there are also higher requirements for the communication performance indicators of wireless local area networks.The Institute of Electric and Electronic Engineers(IEEE),as an international standards organization for wireless local area network protocols,in order to meet the performance requirements of emerging services,with the goal of achieving extremely high throughput(EHT),formulates The nextgeneration wireless local area network protocol standard.In order to improve the communication performance,the EHT standard has made important improvements to a number of key technologies in the PHY layer and the MAC layer,and has pioneered the proposed multi-link technology with great development prospects,which brings a new perspective to the architecture of wireless communication protocols.series of changes.In the wireless local area network communication process,the channel access mechanism of the MAC layer regulates the acquisition of channel resources by each user in the service set.Whether the access mechanism is reasonable or not directly affects the user’s utilization efficiency of wireless time-frequency resources,and is also an important factor affecting the performance index,which determines the service efficiency of the wireless communication system.The introduction of multi-link operation in the EHT standard has brought impact and changes to the current protocol architecture.It has brand-new technical characteristics and enables the channel access mechanism to enter a new field.This thesis closely follows the development of next-generation wireless local area network technology,conducts indepth research on channel access technology under multi-link operation,and proposes an optimization scheme for the rationality of link utilization in asynchronous access transmission mode.The specific research content of the thesis is as follows:In the multi-link asynchronous mode,the number of users on each link is different,the busy and idle conditions are different,and the independence between the links leads to the unreasonable link allocation of the data frame by the MAC layer.The multi-link asynchronous access transmission scheme quantifies the channel busy and idle conditions,introduces the concept of data frame priority,and reasonably allocates services with different priorities according to the channel busy and idle conditions to improve link resource utilization.Finally,theoretical analysis and simulation verification of the proposed scheme are carried out,and it is confirmed that the proposed scheme has obvious improvement in peak throughput and performance maintenance under high user load,which verifies the effectiveness of the scheme.In order to further test the performance of the proposed solution in the real wireless environment,a wireless communication demonstration and verification platform based on the multi-link asynchronous access transmission mode was built using the ZYNQ series development boards of Xilinx Company.The machine has been designed in detail,realized the high-speed DMA interface between Low MAC and ARM that supports multi-link data frame transmission and reception,and developed the Linux kernel driver interface that supports multi-link data forwarding and status feedback.Finally,in a real wireless environment The performance of the platform is tested,and the relevant test results are shown to verify the effectiveness of the multi-link asynchronous access transmission scheme based on channel busy and idle in this thesis in practical application scenarios. |
