Power Management And Protocol Research For Cooperation MIMO Communications In Wireless Sensor Networks

Wireless sensor network (WSN) is a new type of ad-hoc network, which haspotential in wide range of applications including military detection, environmentmonitoring, medical inspection, space exploration etc. MIMO technology which canimprove the channel capacity by the spatial multiplexing, as well as be against theradio channel fading by diversity gain improves the reliability of the wireless link andreduces the energy consumption of the communication.The collaborative MIMO system can reduce network energy consumption andprolong the network survival time with small power consumption and fasttransmission characteristics in wireless sensor network. Specially, clusteringalgorithm is the key step to implement the cooperative MIMO system. However, inwireless sensor network, the traditional clustering algorithms can not meet the needsof collaborative MIMO applications, and the current research of cooperative MIMObased clustering algorithm is still relatively weak.To solve these problems, the major work was done as follows in this paper:(1) The paper improves CMIMO energy model based on clustering algorithms.Taking the influence of the inter-cluster and the intra-cluster communication phaseinto account, which include the number of collaborative number, transmit power, themode of the transmission and the distance to the effect of total energy consumption,the paper analyzes the transmission energy. In order to reduce the total energyconsumption, the number of union collaborative node, transmission energy andtransmission mode are used. The simulation proves that the improved energy modelcan effectively reduce the total energy consumption through simulation.(2) CMIMO protocol which combines multiple protocols and algorithms isproposed. NDP (Neighbor Discovery Protocol): In order to guarantee the energybalance and prolong network lifetime, CSMA/CA mechanism is triggered to build thecluster or re-build cluster through monitoring hello packets. The clustering algorithmof MIMO: In the process of cluster, the role of MIMO is considered. Meanwhile, thealgorithm select MCH/CN/non-CH node under different criteria. SynchronizationAlgorithm: CPREQ packet acts as a synchronization signal, which can achieve thecluster headers sending and receiving the data simultaneously. Routing algorithms: theshortest routing algorithm is improved to reduce the total energy consumption, whichincludes the best transmission path and the best routing hops. By improving the above protocol algorithm, CMIMO protocol effectively optimize collaborative MIMOcommunication performance.(3) The paper completes a performance simulation of CMIMO protocol. In orderto analyze the impact of different network size, inter-cluster communication range, thenumber of network nodes and other factors to energy consumption, hops, transmissionmode and the life cycle, the simulation is done. The results indicate that the CMIMOprotocol outperforms DCA protocol, especially in large scale or long distancetransmission network.