Research On Access Scheme Of 60GHz Millimeter Wave Communication

With the development of science and technology,the era of Internet of things is coming.Today's communications bands are increasingly crowded.Huge bandwidth and ultra high data transfer rate make millimeter-wave(MMW)communication becomes a research hotspot.But its huge potential value also comes with some drawbacks,severe path loss,smaller coverage,high cost and so on.To increase the distance of MMW communication,the application of beamforming technology has been widely recognized.This thesis makes an in-depth study of the access delay and link stability of MMW communication and puts forward my own views and schemes.The initial access of MMW communication is the key point to improve user experience.firstly,the beam training schemes of IEEE 802.11 ad and IEEE 802.15.3c are described,also the application scenarios,performance and emphases of each scheme are compared and analyzed.Then the concept of hybrid beamforming was proposed based on the beam training scheme of IEEE 802.11 ad.Hybrid beam training build on the idea of grouping STA(Stations),for different STA,appropriate beam training programs were selected,separate the emphasis on access between different STA,under the condition of ensuring access,the beam training program with the same emphasis as the self is selected.Because of the use of iterative beam training scheme,access delay can be reduced to a certain extent,closer to the distance from AP(Access Point),STA that can use iterative beam training methods have a larger experience.it also reduces the time spent on overall access,increase efficiency of initial access.Then,based on the mixed access scheme,the dynamic hybrid access scheme is proposed.The software definition network based on OpenFlow is designed to provide related topological information for the implementation of the dynamic hybrid access scheme.Finally,the advantages of the proposed scheme are verified by comparing the performance of the three schemes.For the problem of link interruption caused by blocking,a multi-link scheme based on heterogeneous network is proposed,assisted by a low frequency network,STA can link to alternate AP after the current link is interrupted,continue to process unfinished business.Simulating the distribution of STA using the Poisson process and simulating the distribution of AP using a hard-core process,do the most intuitive display of the feasibility of multilinks in spatial distribution.Finally,the performance analysis of multi-link,this thesis uses the open Jackson network model,the movement of business between nodes is seen as a STA available AP switch.Through the comparison of the overall business processing time of single link,double link and triple link,the performance and feasibility of double link are verified.It was also found that the performance of three links was similar to that of single links,There is no performance improvement,but the complexity of the network is increased,resulting in a time-consuming increase.