Research And Design Of DRM Receiver System

As a kind of important wireless transmission media, traditonal AM radio working on short-wave and middle-wave below 30MHz, has the advantages of simple modulation technology, wide coverage, long transmission distance, portable and cheap receiver. However, with the rapid development of digital, micro-electronic and wireless technology, on one hand, for a lot of media provides audio, image, text and other multimedia information, people can really enjoy the high quality programmes. On the other hand, AM radio remains traditional analog technology, especially the deterioration of electronic magenic environment attributed to the fast developing of communication services, thus the receiving effect of AM radio is not as excellent as before. Therefore, facing serious challenges of other media, the existence of traditional AM radio is threatened dramatically. People long for communication technology that can make full use of frequency resource below 30MHz, keep good features of traditional AM radio and improve the notable shortages. It is conspicuous that digitalization of AM radio is the optimal choice to solve the problem.Nowdays, there are three methods in digital radio system——Digital Satellite Broadcasting(DSB), Digital Audio Broadcasting(DAB) and Digital Radio Mondiale(DRM). Among all three methods, DSR cannot be applied in system of ground transmission, DAB is the technology of audio radio digitalization which focuses on the frequency period between 30MHz and 3000MHz, so DAB cannot meet the demand of digitalization of analog AM radio. DRM technology, working below 30MHz, perfectly solves the problem of digitalization of AM radio. DRM has been the world standard of digital AM radio and will definitely replace traditional AM radio. What is more, DRM not only keeps the traditional strong points of AM radio, but also solves several drawbacks of AM radio, for example, it obviously improves audio quality and anti-disturbance ability, and offers multimedia information and so on. The most outstanding advantage of DRM system is the smooth transition from AM system to DRM system.With the concerns of DRM all over the world, DRM receiver will become the key point of popularity of DRM system. This paper studies the DRM system protocol deeply. According to the functional requirement of DRM receiver system and specific comparison among several solutions, the paper applies DaVinci platform to complete the design of DRM receiver system based on software radio technology. Furthermore, the paper designs and completes a kind of experimental platform of DRM receiver in order to testify DRM receiver software and meet the communication requirement of RF module and DaVinci EVM. The platform can put the analog audio signal from RF module to PC through sound card, or put the digital signal from AD converter to PC through USB interface. Finally, the DRM receiver software and circuit design have been proved by DRM receiver software on PC. Meanwhile, this platform supports the data returning function, that is to say, the data processed by PC returns to DA converter through USB interface, then the DRM audio signal can be recovered. This design not only verdicts software and circuit design, but also mostly accomplishes the functions of DRM receiver.