Research And Application Of LoRa System With Low Power And Wide Area

With the continuous development of information technology,the Internet of Things has become an important direction of current social development.The low-power wide-area coverage communication technology has great development in the IoT application scenario.LoRa has received a lot of attention due to its ultra-low power consumption and wide-area coverage,which solves the problem that the traditional IoT communication technology cannot achieve simultaneous low power consumption and long transmission distance.Firstly,the LoRa communication terminal and LoRa gateway in the LoRa communication system are designed and implemented.The LoRa terminal is based on the low-power versions of the microprocessor and the SX1276 with a wide frequency domain output range and ultra-low acceptance sensitivity and verifies its performance.The LoRa gateway uses a combination of SX1301 and two SX1255 to achieve massive node data reception.In addition,we proposed radio frequency receiving circuit optimization scheme.Then test and analyze the communication performance and terminal power consumption of LoRa terminal and LoRa gateway.It realizes that the communication distance between the terminal and the gateway exceeds 10 km in the urban environment,and the indoor environment transmits 13 floors reliably.Power consumption test and analysis is done in three modes.Secondly,the thesis proposes a design scheme of intelligent irrigation system based on LoRa.The LoRa intelligent irrigation terminal and multi-function LoRa gateway suitable for outdoor complex environment are designed and implemented.The three working modes in the LoRa WAN communication protocol cannot meet the requirements of low power consumption and low latency of application layer commands,then,we propose a communication scheme with a terminal variable length sleep period,which is 2%higher than the Class A communication mode,reducing the 70%execution delay of the downlink command;compared with the Class B mode,the power consumption is about 53.2%under the same delay;to further improve the terminal life,the infinite battery design scheme in the intelligent irrigation scenario is verified.The scheme effectively improves the life of the equipment,and under certain conditions,the irrigation terminal can be infinitely extended.