Research And Implementation Of Key Technologies Of Multi-Channel Emergency Broadcast

Multi-channel emergency broadcast system refers to a broadcast system that transmits emergency information using various channels such as FM network,terrestrial digital TV and cable digital TV.Various disasters have occurred in China.The establishment of a comprehensive emergency broadcasting system can greatly facilitate disaster prevention and relief work and maximize the protection of people's lives and property.In the critical period of accelerating the construction of emergency broadcasting systems,the State Administration of Radio,Film and Television has formulated the “Temporary Technical Requirements for County-level Emergency Broadcasting Systems”,which stipulates the basic framework for the construction of county-level emergency broadcasting and the overall format of preliminary instructions.On this basis,based on the design and implementation of the key equipment in the system-the township / village emergency broadcast signal processing equipment as a clue,the key technologies such as communication protocol,digital signature and signal processing flow in emergency broadcast are studied.1.The requirements for emergency broadcast communication protocols are insufficient and cannot be applied in engineering applications.Based on the “Temporary Technical Requirements for County-level Emergency Broadcasting System”,this thesis refines,improves and designs the communication protocols,and forms a set of emergency broadcasting communication protocols available in engineering practice.Including FM broadcast data format,IP network data format,DTMB/DVB-C data format and backhaul data format.2.This thesis implements the emergency broadcast digital signature algorithm,selects the national secret SM2 algorithm as the system's digital signature algorithm,and implements the Libtommath large number operation library on the Zynq 7010 chip.3.This thesis designs the emergency broadcast signal processing flow,based on the signal processing equipment main control chip STM32F767 designs software system,mainly including software processing such as message processing,audio processing,data transceiving and security verification.Receiving and processing FM transmission data,IP network and DTMB/DVB-C channel transmission data.Finally,the test environment was set up to test the digital signature processing of the emergency broadcast signal processing equipment,the reception and transmission of FM broadcast data,the reception and response of IP network data,and the DTMB/DVB-C data reception.Verifing the rationality of supplementing and perfecting the communication protocol;the correctness of the digital signature algorithm implementation process and signal processing process.