Narrowband wireless communication system and method

The invention belongs to the technical field of rail transit. The invention discloses a narrowband wireless communication system and a narrowband wireless communication method, the narrowband wirelesscommunication system is used for communication between vehicle-mounted equipment and ground equipment, the narrowband wireless communication system comprises an application layer, a security layer, adata link layer and a physical layer, wherein the application layer receives or outputs communication data for interaction between the vehicle-mounted equipment and the ground equipment; the securitylayer adopts a secure transmission protocol to ensure the information security of communication data and the transmission security of the communication data; the data link layer provides processing and output of communication data; the physical layer transmits a bit stream on a bottom wireless channel, performs source channel encoding and decoding, modulation and demodulation on communication data, and sends and receives s