The Spatial Reuse Technology In 60GHz Millimeter Waves Wireless Personal Area Networks

In recent years, along with the sharp increase in the demand for the application needing several gigabit rate in the dense scenes such as conference rooms,office cubicles and living rooms, how to solve the problem of dense scenes has become an advanced research hotspot. For the shortage of band resources, it is difficult to meet the needs of super rate in the LTE and WLAN systems, while the large bandwidth of the mm Wave WPAN with the 60 GHz makes it possible. As 60 GHz signal has high fading and good orientation, its spatial reuse has great potential. In order to solve the problem of dense scenes, an efficient algorithm of spatial reuse must be designed to make more links with very small mutual interference transport in the same time slot, reducing the degree of competition of the dense network scenarios. The applications based on quality of service(QoS) are growing, such as huge amounts of download, high quality of interactive games and high-definition video. Different types of application have different QoS requirements and even different links have different QoS requirements. Therefore, another problem I am trying to solve in this thesis is that how to make the QoS requirements of each link be satisfied. A new spatial reuse algorithm must be designed, which even further improve the degree of spatial reuse.In order to solve the two problems above, the proposed approaches are respectively the global maximum coexistence probability algorithm(GMCP) and the global maximum coexistence probability based on QoS(GMCP-QoS). By adopting the method of recursive scheduling,the GMCP algorithm can obtain the global optimal solution to the spatial reuse problem, and the GMCP has used the dynamic programming method to greatly reduce the time complexity. The GMCP-QoS consists of the channel time allocation algorithm CTA-PSO based on particle swarm optimization, the global modified maximum coexistence probability algorithm(GMMCP) and the adaptive mechanism of the control factor of channel time.The results obtained in this thesis include the higher spatial reuse degree and the maximum QoS experienced by each link. Compared with the other classic spatial reuse algorithms, the higher spatial reuse degree is obtained by GMCP. As the competition degree of wireless resource becomes tougher, the obtained gain becomes larger. The reason is that the global optimal solution of the spatial reuse problem can be carried out by GMCP. GMCP-QoS not only makes the QoS maximum for all the links, but also improves the spatial reuse degree. Compared with the GMCP algorithm not based on QoS, GMCP-QoS algorithm further improves the spatial multiplexing gain. The reason is that the spatial reuse criteria is reasonably redesigned according to the change of the non-fixed length CTA.The impacts of the obtained results are that the problem of dense scenes is successfully solved and that different QoS requirements of each link has been met. By the above algorithms, the higher spatial reuse degree is obtained, which makes more links transmit at the same time slot in a network and improves the system performance. The denser links among the scene are, the tougher the competition degree of wireless resource is, and the higher the gain of the proposed algorithms is. Thus, the problem of dense scenes is successfully solved by the two algorithm proposed in this thesis. The problem that each link has different QoS requirements has been successfully solved by the GMCP-QoS algorithm, which maximizes QoS experienced by all the links.