Research And Realization Of Data Rate Conversion Technique In Multi-rate Wideband Modem

Wide-band satellite communication is of great importance to the future satellitecommunication systems, modern satellite communication systems mainly use all-digitalmodem architecture, among which data rate convert technique is an important issue，andthe development of data rate convert technique is of significant meaning to theoptimization and power saving of all-digital modem system.Based on the program <wideband Modem of rate-change satellite onboard Equipment>，several issues about data rate convert technique are deeply discussedand analyzed.First，the scheme of system layout is carried out, then combining the system’sperformance, three application scene are bring forward, separately applying CIC filter,polyphase filter and farrow based interpolation filter to the integer data rate conversion,fractional data rate conversion and arbitrary data rate conversion.Second, the principle of CIC filter is presented, the performance of CIC filter isalso analyzed in the first part, aiming at practical demand, a improved CIC filter isintroduced at second part, which show better performance than the traditional CIC filter.Following in the article, the principle of polyphase filter is presented in the firstpart, combining the Noble identity and polyphase structure，an efficient structure aboutfractional data rate conversion is recommended，simulation and analysis for the efficientstructure is also presented，the realization details of the efficient structure is carried outalso in the end.Finally，introducing the principle of farrow based interpolation filter，meanwhile，combing Gardner timing recovery loop, simulation and analysis of the farrow basedinterpolation filter is presented，besides,the realization performance of the farrow basedinterpolation filter is carried out in the end.