Study On Virtual MIMO Communication Based On V-BLAST Processing In Wireless Sensor Networks

Wireless Sensor Network (WSN) is an emerging technology, which incorporatessensor techniques, nested computation techniques, distributed computation techniquesand wireless communication techniques. Wireless Sensor Network can be used for testing,sensing, collecting and processing information of monitored objects. As Wireless SensorNetwork is generally deployed in very complex environment and meanwhile sensorbatteries are difficult to replace, so the whole network function will be influenced ifsensor node batteries run out. As to this energy-confined network, energy efficiency is aprincipal issue. It is important to ensure energy efficient usage of every node in thenetwork so as to prolong the whole network lifetime, which is a key aspect to WirelessSensor Network.By combing the key mobile technology of new generation communication MultipleInput Multiple Output (MIMO) with Wireless Sensor Network, the VirtualMIMO(VMIMO) communication system is formed, which shows better energy efficiencythan traditional Single Input Single Output (SISO) communication model. Due to simpleencoding and decoding process, MIMO space-time code Alamouti code is widely appliedin energy-confined sensor networks. As Alamouti scheme requires transmitter-side sensorjoint coding cooperation, which will leads to energy-consuming. So simpler VirtualMIMO sensor network communication system model based on Vertical Bell LaboratoriesLayered Space Time (V-BLAST) processing shows its energy efficient advantage. Andwe introduce Minimum Mean Square Error-Ordered Successive Interference Cancellation(MMSE-OSIC) algorithm into model above in, order to save the energy consumption ofthe whole sensor network. The main content in the research of this thesis includes:1,Review the history of Wireless Sensor Network, introduce and make a summaryon the whole Wireless Sensor Network, then study and analyze the recent main problemand hotspot of Wireless Sensor Network.2,On the basic analysis of MIMO principle, we make the further exploration on thespace-time code technique, especially in layer space-time code and its detectionalgorithm. 3,On the basis of applying the MIMO technology into the energy-confined, widelydispread Wireless Sensor Network to form the Virtual MIMO communication systemmodel, we adopt Virtual MIMO sensor network communication system model based onV-BLAST detection processing. Then we study V-BLAST detection processing onreceiver side and introduce the MMSE-OSIC algorithm on the receiver side in order tomake every node on the transmitter side consumes less power to meet the outputrequirement comparing with MMSE and QR algorithm, which will enhance energy usingefficiency of the whole network.4,In the traditional wireless network the energy consumption mainly concentrates inenergy consumption caused by practical wireless transmission. But in energy-confinedWireless Sensor Network the energy consumption of circuit module cannot be neglected,which is different from traditional wireless network. Through the research on VMIMOcommunication model based on V-BLAST processing in the Wireless Sensor Network,the transmitter side energy consuming is saved by applying with MMSE-OSIC algorithmon receiver side. On the basis of saved energy on the transmitter side, we make theanalysis about total energy consumption combing with the transmitter side circuit moduleenergy consumption during the whole communication process. Based on the analysis ofthe experimental simulation, the introduction of MMSE-OSIC algorithm acquiresefficiency on saving the total energy consumption during the whole communicationprocess in the Wireless Sensor Network and makes the positive effect on prolongingnetwork life.