Research And Implementation Of Ultra-low Power Sustainable Wireless Sensor Networks

Wireless Sensor Networks is a network system consisting of some wireless sensor nodes.Each node can collect environmental data and transmit data through wireless communication.It has been widely used in military,intelligent transportation,environmental monitoring and other fields.In traditional wireless sensor network applications,the network lifetime is limited by the node battery capacity because of small size of nodes.Moreover,wireless sensor networks have a large number of nodes and a wide distribution range.So replacing batteries for all nodes is unachievable and extremely costly.In order to solve the above problems,this paper proposes an ultra-low power sustainable wireless sensor network system.It can collect electromagnetic energy from the environment through wireless energy transmission technology and convert it into electrical energy to power the nodes.In addition,by introducing wake-up radio technology and ambient backscatter technology,the power consumption of the wireless sensor network is further reduced,thereby extending the service life of the network.The work of this paper mainly includes the following aspects:(1)Design an ultra-low power sustainable wireless sensor network system and propose an EW-MAC protocol for this network system.The ultra-low power sustainable wireless sensor network system includes a wireless energy harvesting module realized by wireless energy transmission technology and a wake-up function module realized by ambient backscatter technology.They solve the energy and power consumption problems of the network.According to the technical characteristics of this network system,this paper proposes the EW-MAC protocol and develops an ultra-low power working mode suitable for this network.The simulation proves that the protocol can fully utilize the advantages of the wireless energy harvesting module and the wake-up function module effectively reducing network energy consumption,shortening transmission delay,and prolonging network service life.(2)Complete the design and implementation of wireless energy harvesting modules in ultra-low power sustainable wireless sensor networks.This paper designs various parts of the wireless energy harvesting module,including energy harvesting antenna,matching network,rectifier circuit,DC boost circuit and energy storage circuit.Then,this paper also completed the physical production and functional experiment of the module.The experimental result shows that the wireless energy harvesting module can collect environmental RF energy to power the nodes and realize the sustainable operation of the wireless sensor network.(3)Complete the design and implementation of wake-up function modules in ultra-low power sustainable wireless sensor networks.This paper proposes to use the principle of ambient backscatter to realize the wake-up function module in ultra-low power sustainable wireless sensor networks.Then this paper completed the design and implementation of the ambient backscatter communication transmitter and receiver.Because of the ultra-low power consumption characteristics of the ambient backscatter communication,the wake-up function module enables the wireless sensor network to implement the RF wake-up mode.So the network system can reduce energy waste and achieve ultra-low power consumption and sustainable operation.