Baseband Algorithm Analysis And The Implementation Of Digital Trunked Interphone

Wireless digital interphone is economical and practical with advantages of instant communication, low cost and convenience to use and free communication cost. Therefore, it is widely used in civil fields and conducting emergencies. Especially in the cases of emergency conducting and environment without mobile network covering, wireless digital interphone plays a remarkable and irreplaceable role. This thesis puts focus on the analysis of the key algorithms for baseband in DMR digital interphone and introduces an innovative hardware design for digital interphone terminal baseband module based on MCU and DSP of DMR new communication protocols.The thesis introduces DMR generally along with the current development and research background of wireless digital interphone. Secondly, it introduces the various channel encoding and decoding programs in the processing, including CRC, Convolutional coding, Viterbi decoding, interleaving etc. and simulates the error rate of full-rate voice channels. Thirdly, it gives a detailed formulas and instructions for the principle of GMSK modulation and demodulation. Finally, it illustrates in details on the generation process of channel encoding and decoding and GMSK modulation and demodulation along with the debugging methods and results.