Research Of Digital Audio Broadcasting Signals Simulation

Radio is still playing an important role in social life today when the Interent is popular.Analog broadcasting has shown shortcomings in the current period.As a new generation of broadcasting technology,digital audio broadcasting(DAB)is taking the place of the traditional analog radio.DAB has the advantages that traditional analog broadcasting does not have,such as of high frequency spectrum usage,low audio data rate,good performance in sports reception,and so on.Since DAB signals are more complex than analog signals,the exploration of DAB signal simulation has certain practical value for the development of DAB transmitting and receiving systems.According to the current resources,this work mainly studies the following aspects:1.DAB system principle analysisThe DAB system principle is deeply studied based on the DAB protocols.The principles of audio encoding are discussed.The data frame components(fast information channel,main service channel,and synchronization channel)are researched,and the channel division principle and data encoding are thoroughly understood and explained.And the principle and implementation of multi-carrier modulation technology is explored.2.DAB digital signal simulationThe analog audio data is translated into DAB digital signal with the computer software written by C/C++.This part is consisted of three modules: analog signal conversion to digital signal audio coding,channel coding to improve transmission reliability,RF signal OFDM(Orthogonal Frequency Division Multiplexing)modulation module.3.DAB transmission systemThe hardware platform of DAB transmission system is the AV1443 vector signal generator.By loading the RF I/O data generated by software modules,it achieves the DAB transmission in the arbitrary waveform operation mode of AV1443.4.The application of recognition of constellation mapping based on machine learningConstellation mapping recognition is a fundamental part of wireless communication.The DAB system uses QPSK(Quadrature Phase Shift Keying)modulation to identify phase information using the look-up table method in current system.Based on the advantage of machine learning in recognition,it is explored about the feasibility of the applications of PSK modulation pattern recognition using machine learning(support vector machine).This thesis is based on DAB principle for conducting system implementation.The research has expanded the PSK modulation pattern recognition technology,which has certain application values for the construction of domestic digital audio broadcasting.