Study And Implementation Of GMSK Modem Based On CMX589A

Modulation and demodulation technology are important part of the mobile communication system.GMSK modulation have been widely adopted for many mobile communication systems and Satellite communication systems because of many advantages,such as better spectrum efficiency,stronger anti-interference performance,low Bit Error Rate.Currently,there exists various solutions to carry out GMSK modem,ASIC and general programmable devices'solution is still in developing.This paper presents a new method to design GMSK modem based on CMX589A and FPGA ,which combines ASIC device's advantages of high precision,stable and reliable performance and general programmable device's ability of easily software updated. Therefore,the implementation of GMSK modem is innovative and of great significance in theoretical research and practical application.In this paper,the development and research progress of GMSK modulation technology both at home and abroad are firstly introduced,then the solution of GMSK modulator and demodulator based on CMX589A and FPGA are presented by analyzing characeteristic of current methods.Secondly,the hardware platform of GMSK modem is designed according to the system's requirements,the principle and design of each part is given in details.Meanwhile,the system's software is designed based on Quartus II and DSP Builder,the results of simulation verify the theoretical correctness of design.Finally,the function and performance of the system are tested on the hardware platform and the results are presented and analyzed.Through test and actual operation,both of the functions and technical specifications meet the design requirements.