Study And Design Of Long Distance Wireless Communication Module Based On LoRa

With the rapid development of wireless communication technologies,wireless sensor networks have been widely used in smart cities,intelligent transportation,and wireless meter reading systems,in recent years.Short-distance communication technologies,such as ZigBee,Bluetooth,and WiFi have been unable to meet the needs of applications for long distance communications.Wide coverage,flexible networking,low deployment cost,good security performance,low energy consumption and large device capacity are becoming the new requirements and challenges in the field of IoT nowadays.At the same time,the development of wireless communication device terminals with low path loss,high anti-interference capability and low power consumption are also the focus and difficulty.In order to meet the demands of the current IoT in terms of distance,bandwidth,power consumption,equipment access capacity,etc.,this paper study the low-power wide area network LoRa technology.And then,analyze the development and prospects of LoRa,as well as the researches of the existing radio frequency modules that based on LoRa.There are some inadequacy in insufficient effective communication distance,anti-interference ability and energy consumption.In this paper,the research and design of wireless communication module based on LoRa technology are carried out in combination with the hardware circuit design techniques.It effectively overcomes the difficulties of terminal equipment in path loss,anti-jamming capability and power consumption,and satisfies the needs of the IoT in terms of power consumption and distance.First of all,the performance indicators,design ideas and overall technologies to be achieved in this paper are clarified and the long-distance wireless communication technology,spread spectrum theory are studied and discussed.Then,the decomposition of the overall technology and the analysis of the key technologies are performed from the aspects of energy transmission efficiency,anti-jamming capability,and low power consumption.By using the EDA software the filter and matching network in the RF front-end circuit are designed and optimal to reduce the path loss,improves the energy transmission efficiency and anti-jamming capability as well.Then,the overall power consumption of the module is reduced through hardware circuit design and software power optimization.And a complete communication module has been formed through PCB plate making,circuit welding and other processes.Finally,a wireless communication module is developed with long distance,strong anti-interference ability and low power consumption after the test and optimizing of the performance.The results show that this wireless communication module realizes effective communication of 6000 m when the transmit power is 20 dBm,and penetrating communication through 7 walls and 5 floors.With the working voltage of 3.3V,the power consumption is is about 140 mA and 50 mA in sending state and receiving state respectively,while it is as low as 10.27 uA in sleeping mode.The average power consumption of the sending device is 11.4 mA,and the average power consumption of the receiving device is 7 mA when it is set 3s periodically.