| With the development of new media technologies such as hd video,the demand of wireless data transmission rate and spectrum resources for wireless communication is bigger and bigger.2.4GHz and 5GHz frequency spectrum resources can not meet this demand.The 60 GHz millimeter wave band has the advantage of big bandwidth and high speed,which has become the hotspot of research.Directional transmission can not only make up for the shorter transmission distance and the large path loss caused by the short wavelength of the millimeter wave,but also bring great potential for spatial multiplexing.IEEE 802.11 ay supports single-user multiple-input multiple-output(SU-MIMO)and multiple-user multiple-input multiple-output(MU-MIMO)technologies.However,the SPSH(Spatial Sharing)mechanism defined in the IEEE 802.11 ad standard and the IEEE 802.11 ay standard draft only applies to single-link spatial multiplexing among multiple pairs of STAs in the same basic service set(BSS)and does not support multi-link spatial reuse.In addition,interference between BSSs in an AP-intensive scenario may be severe,and communication of SP within the BSS cannot be guaranteed.The spatial multiplexing mechanism proposed by 802.11 ay and existing literature does not consider interference suppression and spatial multiplexing about SU-MIMO and MU-MIMO transmissions for multiple inter-BSS in dense scenes.In the process of MU-MIMO transmission,if one of the STAs is seriously disturbed,the entire set of MU-MIMO transmission may not be able to be performed,therefore the mechanisms interference suppression and spatial reuse need to be designed.Based on the spatial reuse mechanism defined by the IEEE 802.11ad/ay standard,the spatial reuse mechanism of SU-MIMO and MU-MIMO is studied in this thesis.First,a SU-MIMO spatial reuse scheme within the same BSS is proposed,and a SU-MIMO spatial reuse mechanism for centralized control and distributed control(Multi-AP)architecture are studied,then the related signaling interaction processes,frame structure,channel measurement and reuse scheme are designed.In addition,the thesis calculates and analyzes the time cost of proposed scheme in different scenarios.The simulation result validates the effectiveness of the proposed scheme,and the spatial reuse gain and throughput performance of the scheme are analyzed based the proposed scheme.Since MU-MIMO transmission requires AP’s participation,and MU-MIMO spatial reuse may only occur between BSSs.In this thesis,the MU-MIMO spatial reuse mechanism is studied separately for two dense scenarios of S-AP and Multi-AP,and the signaling interaction flow,related frame structure,channel measurement and reuse scheme are designed.Furthermore,the interference of mu-mimo space reuse is analyzed,and the mechanism of removing the disturbing nodes is proposed to realize partial mu-mimo reuse.Combining with the channel interference measured by STAs in MU Group,two measurement feedback schemes and four measurement feedback schemes are designed.Finally,the thesis calculates and analyzes the time cost of different schemes under different scenaros.It is verified through the performance simulation that the space reuse scheme proposed in this thesis can realize the spatial reuse of MU-MIMO between BSSs,and the spatial reuse gain and throughput performance of the scheme are analyzed. |
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