Research Of Cluster-based Virtual MIMO Scheme For WSN

Wireless Sensor Network (WSN) is an important part of Internet of Things (IoT),which has being an attractive research topic and been widely studied. Nowadays,WSN has been proposed to apply in many areas such as national security, economics,and other areas of the society. WSN consists of a large number of wireless sensornodes with limited energy resource. How to improve the energy efficiency of anindividual node and the entire network is of great importance.Multiple-Input-Multiple-Output (MIMO) technology is a big breakthrough incommunication technology. MIMO technology deploys multi-antenna arrays intransmission and reception ends, combining with space-time coding. It takes theadvantage of multipath fading to achieve diversity gain and multiplexing gain, so as toimprove the spectrum utilization and channel capacity. Therefore, MIMO can reduceenergy consumption of data transmission. In order to apply MIMO technology in tinywireless sensor nodes, virtual MIMO technology is born. In this paper, the applicationof virtual MIMO technology in WSN is being researched.Firstly, the advantages and characteristics of WSN technology and MIMOtechnology are analyzed. The network architecture, communication protocols,application prospect and routing protocol of WSN are analyzed. The advantages anddisadvantages of various routing protocols are also discussed. After that, the principle,characteristics and advantages of MIMO technology are studied.Secondly, the advantages, feasibility, mechanism of node organization, networktopologies and transmission mechanisms of virtual MIMO in WSN are discussed.Thirdly, a relatively complete virtual MIMO routing scheme based on clusteringand multi-hop is proposed.In large scale virtual MIMO system，organization of nodes is very important.Clustering helps reducing data redundancy and network maintenance overhead, at thesame time, keeping the network stable and making nodes cooperating moreeasily.Nowadays, cluster-based cooperative MIMO is a typical way, where a clusterchooses one or two cluster heads to perform inter-cluster communication. However,most cluster-based protocol adopt periodical re-clustering of the whole network,which produces large scale network reconstruction, leading to massive waste ofenergy resources. The proposed protocol adopts intra-cluster Cluster Head rotation to avoid theadditional overhead caused by the large number of re-clustering. At the same time, aprocedure named "over-jump" is combined with the proposed protocol to balanceenergy consumption as well as lifetime of different nodes and clusters.Finally, the energy consumption models of virtual MIMO node and network areestablished. The effect of the proposed protocol is simulated. The results show that theprotocol can outperform in energy efficiency and balance, compared with traditionalcluster based virtual MIMO.