The Design And Implementation Of The FM Radio Data System

Radio Data Systems was development started20years ago in the European Broadcast Union, EBU, it is a new technology which takes advantage of the spare frequency spectrum resources of the FM radio to achieve extending business. The developers aimed to ease the process of tuning in to a station, especially as the number of broadcasters was increasing and use of alternative frequencies to avoid interference would make it difficult to keep tuned to a certain station. The use of RDS would overcome this problem and will also send the voice message and also transmit the data information; this feature can meet the need of information visualization in the media. At the same time, it has very important practical significance for the use of limit spectrum resources to provide more data services for users.In this paper, the main object of study is the circuit design of RDS encoder in Radio Data System transmitter. The main research contents are as follows:First, according to the technical specification which RDS encoder involved in, we analysed RDS baseband signal waveform, differential encoding, parity coding and frame type which based on the modulation characteristics of data channel, data signal baseband encoder and data signal message format.Secondly, based on the principle and technical specifications of RDS encoder, we designed circuit for the RDS encoder, including circuit program verification, chip selection and the function realization of circuit.Third, combined with data encoding and processing features of RDS encoder, the RDS encoder involved in software part which included the baseband signal processing, check coding, baseband signal data frame output and bi-phase coding, these parts have been designed and implemented on software integrated development platform MPLAB IDE。Finally, we debugged and simulated circuit design and software of the RDS encoder with the use the MPLAB IDE software development platform and analog-digital hybrid simulation software Protues ISIS, in order to meet the parameters required of circuit design and software design of RDS encoder and to achieve RDS encoder funcation which make data information through the RDS encoder could have being a transmitting data signals for FM transmitter.Meanwhile, in order to facilitate follow-up study, we also studied circuit theory and analysis of RDS decoder in Radio Data System receiver and proposed the circuit design of the various components and the chip select to implement the corresponding functions for RDS decoder.