Research And Analysis Baseband Signals Of Digital Radio Base On DMR

Interphone communication plays an important role of mobile communication,and has a great influence in people’s daily life.Due to the disadvantages of the analog interphone appeared gradually, improving and upgrading the analog interphone,is not only beneficial to people’s using,but also has a profound influence on the development of wireless communication. With the interphone convert from analogue to digital in our country, people has a great interest in the research of the interphone.This paper focused on the DMR standard put forward by the European telecommunications standards institute, the DMR standard is low cost,simple technology and support the transition from analog to digital. The paper is fisrtly introduces the structure of the the DMR standard,including voice frame and data frame,and the different function of the information in the DMR standard. Secondly, the paper introduces the hamming code, QR code and Golay code in the DMR standard,and analyzes the performance of the (16,7,6) QR code and its coding/decoding process,to the decoding of the (16,7,6) QR code,it proposed a new decoding algorithm. Then, the paper researchs on the baseband signal processing of the DMR standard, analyzes the design of the shaping fiter of the Transmitter and the process of sampling and decision of the Receiver,discuss the fitering result of the different order and the diffdrent wonders funtion of the shaping fiter,and given the algorithm simulation graph of the. baseband signal processing thought the MATLAB and the CCS. Lastly,the paper analyzes the D/A conversion and the using of the PWM signal,it introduces a way of the D/A conversion of the baseband signal by the PWM signal and the low pass fiter.