Research On The Key Technology For OFDM And FM In Band On Channel Broardcasting System

With the continuous development of the world digital broadcast and the increasing requirement of the new media technology, the practitioners of broadcasting in China have actively explored. With its unique innovative and significant performance advantages, CDRadio, one of Digital Audio Broadcasting, becomes an important candidate of FM digital broadcast standard of China.The biggest feature of this technology is to support the in band digital-analog aliasing simulcast, and is conducive to the smooth transition of analog to digital broadcasting.In the view of CDRadio system researching and developing, the technical background, program design, system implementation, and performance improvement are investigated in this thesis. First, the feasibility of the program is explored with the support of American standard HD Radio, Secondly, the FM radio technology working as the important part in the system is deeply understood and analyzed. In addition, the thesis also designs the model formed of the host computer, actuator, and soft receiver.Due to the unique time-frequency structure, the previous synchronization algorithms will face up with suitability requirements, Taking OFDM’s sensitivity of system timing and frequency offset into consideration, the choice of synchronization algorithm will have a crucial impact on the system performance. The thesis focuses on simulation and performance comparison of synchronization algorithms which are the ML algorithm based on cyclic prefix, the Schmidt&Cox algorithm H.Minn algorithm Park algorithm based on training sequence, and makes a creative improvement of the Park algorithm which is the best option with the lower computational complexity and better performance.Besides, in order to enhance the system performance, digital front-end module, a digital-to-analog separation algorithm, channel estimation algorithms which play a crucial role are all studied in the thesis.Finally, the thesis draws a conclusion and makes an expectation of research area.